Side by Side Cantillon Brett Tasting

It’s been a very long time since my last post. Lately I’ve been even busier than before, which is not unexpected for someone in my position, and homebrewing as well as yeast ranching has, for all intents and purposes, ceased to exist for me. I have been reduced to reading blogs and fantasizing about homebrew over the last few months because I can’t take part in it in real life on account of working seven days a week. Though I have full intentions to brew and make new plates to isolate more goodies, my last brew day was in the spring. Even on weekends I’m stuck in the lab glued to a microscope, dissecting newborn mouse eyes. The situation may be changing as enough eyes have been collected to keep my experiments rolling for at least a few more months. Hopefully, soon enough I’ll start brewing and isolating bugs again.

One of my readers asked for a side by side tasting of the BK C strains and it sounded like a good idea. Besides, I wanted to do this for a long time so thanks for the encouragement.

Left to right: C1-C2-C3

Left to right: C1-C2-C3

The recipe for these beers is simple:

Malt:

US 2-Row Malt 80.0 %
US White Wheat Malt 20.0 %

Mashed at 147˚F.  OG – 1.056. FG – 1.001.

Hops:

German Tradition
1.00 oz
60 Min From End

US Calypso
2.00 oz
5 Min From End

US Calypso
1.00 oz
At turn off

Left in primary for 3-5 months and bottled with table sugar to ~3 vol.

 

I have tasted these beers before and gave some descriptions here and there, but never all together and never with a few months of age on the bottles. So let’s see how they are doing.

 

C1

Appearance: Orange/yellow. Clear with just a little bit of haze. Medium head in beginning, but then recedes to a ring around the glass. Lively carbonation.

Smell: Woody funk in the foreground, followed by sweet, fruity notes. Ripe pineapple and citrus. Allowed to stand and breathe a little, the woody funk goes down and sweet fruitiness becomes more prominent.

Taste: Whoa, it changed a lot since last time I tasted. Initially there is no woody funk at all, and the flavor is malt forward. Barnyard, earthy, wet funk makes an appearance and is almost instantly washed away by carbonation to be replaced by lemon, hay, and woodiness. Lemon and woody funk fight for dominance with lemon being the victor in the end and lasting through the finish. If I didn’t know this this has never even touched wood, I would argue that this beer was barrel aged for too long due to really woody-barrelcharacter. Very dry and just a little tart. Enough to make my mouth water. A bit vinous, like dry white wine. Citrus, citrus, citrus.

Mouthfeel: Medium. Surprising for such a dry beer, but it’s by no means thin. Mouth filling, even somewhat coating.

Overall: This beer has improved a lot. Rather than weird woody funky fruity beer with individual characteristics not really playing harmoniously, as was the case just a few months ago, I feel like now it’s a much better brew. Things just work, and work well. There is too much woodiness for me, but otherwise it’s a very pleasant and refreshing beer. Perfect for the summer. I’m really interested to see how it continues to develop.

C2

Appearance: Yellow/orange, much like C1, but brighter. Clear with a little haze. Champagne-like carbonation with a lot of head at first, but then goes down with nothing remaining, just bubbles coming to the surface.

Smell: Woody funk, but much less pronounced than C1. Grassy, sweet, fruity, apricot. More appealing to me than C1.

Taste: Also quite different than it was the last time. Malt forward, very subdued woody funk that lets fruitiness and even what seems like sweetness to come through. I’m sure I can taste just a hint of strawberry on the overall fruity background here and there. Dry and vinous, tart, but less so than C1. Woody funk comes back in the end and gets replaced by hop bitterness.

Mouthfeel: Fuller than C1. I noticed before that C2 seems to produce almost an oily mouthfeel and this is the case. It’s almost oily, almost velvety, just strange for such a dry beer.

Overall: Not as refreshing as C1, but interesting nonetheless. It’s pleasant, and the absence of dominating woodiness is a big plus.

C3

Appearance: Straw yellow and crystal clear. Initial head recedes to nothing, same as C2.

Smell: Similar to C2 in terms of less woody funk, but more herbal, grassy, Cantillon-like. Does not smell sweet, though one can still detect pineapple notes.

Taste: Fruit forward. Sweet, pineapple, white apple, general fruitiness. Woody funk makes a sudden and strong appearance and disappears leaving light bitterness and gentle woodiness behind. Probably the least woody of the three beers. Tart, dry. For some reason really makes me think of big, juicy, sweet white apples. Funk comes back in the aftertaste.

Mouthfeel: Light. Lighter than C1 or C2.

Overall: Interesting. Not bad, but I feel like it needs more age. Fruity.

 

It’s intriguing that they changed as much as they did and I’ll be sure to give them another official tasting maybe in a year or so. Overall I’m pleased with the way they turned out. Stay tuned for more posts coming in future!

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Homebrew Alley VII Homebrewing Competition

Hey everybody! Remember me? That yeast rancher from Brooklyn, NY? Yes, that one! Well I’m still alive and kicking! I apologize for the long hiatus in posting yeast experiments, but the truth is that I’ve been just too busy in lab. With grants due in a couple days there has been quite a push to come up with ideas and preliminary data to test them. Since the primary aim of this particular grant is my thesis project, I hope you can understand how it takes precedence over brewing and yeast ranching for the time being. Hopefully after submitting it this week things should get back to normal and I’ll no longer slave away until 10-11pm every day and will have time to brew some beers and ranch some yeast. The next yeast experiment is already planned out and will probably be posted in about a week for the benefit of a portion of my readers who have been asking me to do it for some time now. Until that sweet time comes I’ll try to entertain you by telling you how my first homebrew competition since 2011 went.

This year Homebrew Alley had over 700 entries, making it the biggest one yet. I picked it because it was local and there was no need for shipment as long as I paid the entrance fees and dropped the bottles off at the appropriate location. As you probably know, I always refer to competitions as a waste of beer and money because of my previous experiences with oxymoronic comments from judges (like the famous “dry and cloyingly sweet”) as well as just plain wrong statements such as describing Brettanomyces character of beers that have never been touched by Brett. This year I thought I’d give it another try mainly to see what people think of my sour brews. To my surprise, my Berliners ended up taking 1st and 3rd places in the categories entered. Another surprise was the scores for the Witch Poison Gruit. Though it received the lowest score I’ve ever gotten, it was nice to see that the judges accurately identified its characteristics, which they thought to be fermentation flaws, but instead came from the ingredients. To me that shows that this time people judging the beers were competent and didn’t just make things up.

Rather than posting the photos of the score sheets I’ll just give you the text because some of them are written in extremely illegible hand or just cut off mid-sentence.

So, on to the scores!

photo-21

Not sure why they sent me two 3rd place ribbons.

xxxx = can’t be read without a cryptologist.

 

Berliner Weisse

Entered in Category 17 A

 

Judge #1:

Aroma: Moderate sour aroma (both lactic and slight acetic). Moderate leather, hay – nice. Complex. No hops. 9/12

Appearance: Pale yellow. Very slight haze. Pours with very low white head that dissipates immediately. 2/3

Flavor: Aggressive, but not overpowering sourness, mostly lactic. Bone dry. Mild Bretty barnyard flavors. Hints of wheat and honey in background. No hop flavor. 16/20

Mouthfeel: Effervescent, very prickly, no astringency or warmth. 5/5

Overall Impressions: Excellent Berliner. Maybe a little big for the style, but delicious. 8/10

Total: 40/50

 

Judge #2:

Aroma: Very mild sourness. Mostly lactic. Allows some wheat to shine through too. No hops. Some barnyard xxxx in there too. 8/12

Appearance: Pale golden. Opaque. Very slight white head xxxx energy and fades quickly! 2/3

Flavor: Sharp sourness – very lactic with supporting horsey and barnyardy. No fruit or yeast character evident. 16/20

Mouthfeel: Super light body. Low carbonation level. Dry as heck! No booziness. 2/5

Overall Impression: Undercarbonated for the style. More would have made it livelier. A little more general “funk” than a Berliner typically has. But this is a very tasty Berliner. Should get even better with age. Thanks for entering! 7/10

Total: 35/50

 

Final Assigned Score: 37.5

Place awarded:  3rd

 

My thoughts: It’s interesting how two people drinking the same beer differ in carbonation description. It was also a little surprising to see that it’s aggressively sour because I always thought of it as very mild.

 

Troubadour (Berliner with raspberries)

Entered in Category 20 A

 

Judge #1:

Aroma: You can smell the sour as it pours. Tartness dominates, followed by a hint of “stinky feet”. Raspberry in the back (very true to life raspberry at that). Slight petrol behind, which is complementary. 10/12

Appearance: Pours with large head that rapidly disperses to film on top, clear, light pink/straw color. 3/3

Flavor: Sour tartness dominates. The raspberry flows behind. Otherwise clean lactic strong. Petrol notes towards end compliment. Some barnyard character as well. 17/20

Mouthfeel: High carbonation, light body, puckering, dries out. 5/5

Overall Impression: A delightful beer. The level of tartness is on the higher end of the spectrum for a Berliner and also has a nice depth. Displaying nice lacto as well as Brett character. This might be intense for some, but I love it. Beautiful job! 9/10

Total: 44/50

 

Judge #2: actually same person as Judge #1 from Berliner Weisse

Aroma: Strong grainy wheat aromas accompanied by a touch of green apple-like sourness, a touch of acetic acid and a hint of raspberry. Slight phenolic. No hops. 10/12

Appearance: Pours fairly clear. Salmon color with a tall white head that dissipates quickly. 3/3

Flavor: Wheat apparent along with an aggressive sourness (combo lactic and acetic, more lacto). Mild plastic phenolics. Raspberry barely perceptible, but there. Hops not apparent – good. 17/20

Mouthfeel: Medium body (maybe a bit high for the style). Very highly carbed – nice. Mouth puckering, prickly. 4/5

Overall Impression: Very nice Berliner. Could use a touch more raspberry. Maybe a little big for the style. 8/10

Total: 42/50

 

Final Assigned Score: 43

Place Awarded: 1st

 

My thoughts: Never expected this! When I brought this brew to a homebrew meeting and people gave it very positive and enthusiastic reviews I thought they were just being nice. I guess this really is a successful combination. Now I just don’t have an excuse to not make this again!

 

Schismatic Dubbel

Entered in Category 18 B

 

Judge #1:

Aroma: Raisin, stone fruit, malt sweetness, restrained hop character. Sweet fruity ester character from yeast is very restrained. 9/12

Appearance: Pours with a thick, tan, airy head. Reddish-brown color. Clings to glass very beautifully. 3/3

Flavor: Salted caramel sweetness is dominant. Fruity yeast characteristics are very pleasant and has a strawberry quality to it. Alcohol warming is very noticeable at end (and on breath afterward). Toffee is dominant. 15/20

Mouthfeel: Medium body with medium-high carbonation. Initial creamy texture which leads to an alcohol warmth and slightly chewy. 4/5

Overall Impression: Very well executed beer in terms of style. However, alcohol warmth could be toned down just a touch and you may want to experiment with slightly less caramel malts. I really enjoyed this beer. 7/10

Total: 35/50

 

Judge #2:

Aroma: Big malty nose with some toffee notes and a little clove. 8/12

Appearance: Dark amber color with beige head. Great retention. Fairly clean. 3/3

Flavor: A lot of toffee + caramel. Very malty. Some raisins + phenols. Nicely balanced. Whole lotta toffee! 10/20

Mouthfeel: Medium-full mouth. High carbonation. Creamy. No alcohol warmth. 4/5

Overall Impression: Good example, but it falls a little flat in the end. 6/10

Total: 31/50

 

Final Assigned Score: 33

Place Awarded: none

 

My thoughts: This is not bad for a dubbel brewed in 2010 I think! Interesting how they differ in terms of alcohol warmth. Sounds like I should try recreating it.

 

Witch Poison Gruit

Entered in Category 17 E

 

Judge #1: Non-BJCP

Aroma: Big smokiness xxxx. Light cooked vegetables. Cabbage aroma. Some baby diaper, tons of diacetyl. Malt aroma – low to none. 3/12

Appearance: Golden. Hazy billowy head. Fizzy like soda. Head disappeared quick. 2/3

Flavor: Sharp sourness with Bxxxx smokiness. Smoke is peat-like with some bacon. Tart. Not a ton of malt. 7/20

Mouthfeel: Med-low boon. No astringent. No alcoholic. Tart. 3/5

Overall Impression: Unfortunately the diacetyl and smoke in this beer make it hard to drink. It is complex, just not the right kind of complexity. 5/10

Total: 20/50

 

Judge #2:

Aroma: Slight fishy aroma and a xxxx dominant cherry wood smokiness. No hop aroma. 5/12

Appearance: Pours orange-gold with thick head that dissipated almost immediately. Cloudy, but appropriate for style. 2/3

Flavor: Very complex, with smokiness and somewhat unusual fermentation characteristics. Strong lactic tartness, appropriate, but (not sure what happened here. he just cuts off) 8/20

Mouthfeel: Light body and medium carbonation. No alcohol warmth or astringency. Very strong and lingering slickness from lacto and diacetyl. 1/5

Overall Impression: Very strong lactic taste, but not very refreshing. Need to clean up the lactic off flavors (smokiness, fish) and reduce the slickness (probably combination of lacto and diacetyl) 4/10

Total: 20/50

 

Final Assigned Score: 20

Place Awarded: none

 

My thoughts: This is the lowest scoring beer I’ve ever had, but despite that I am strangely happy about it. The judges described it pretty accurately, but didn’t know that it’s all not fermentation flaws, but derived from the ingredients themselves. Smokiness, fishiness and bacon are contributed by a huge amount of peated malt. Vegetative character is contributed from the juniper branches, pepper and lemongrass. Slickness is probably from the rye. In any case I agree with them that the vegetal smell isn’t very appealing. It also looks like my suspicions about using rye and darker malts in a no-boil beer is not a good thing. Something in them doesn’t play nice with the bugs. Don’t know what to make of diacetyl as I haven’t noticed it. It probably wasn’t the best idea to enter it is a Gueze, but I just didn’t know where else to stick it. All in all this beer is what it is and they got it pretty much right. Most important thing is that I enjoy it in the summer, and strangely, so does my mother who hates beer.

 

There you have it. Looks like my Berliners are better than I thought and this gives me more incentive to continue with funky and sour brews.

As I mentioned before, I am still very much alive and intent to keep homebrew funky yeast science going strong. In recent days I’ve been getting more emails asking about the Cantillon Iris isolates as well as whether or not I’ve isolated some new strains. The answer is a definite YES. There will be more Iris strains in upcoming weeks and there will be more unique bugs isolated soon too. Hopefully after this week I’ll be able to get back to it.

Cheers!

Cascade Kriek Bug Isolation Part I

Greetings, fellow yeast mates!

First of all I’d like to wish you all happy holidays and I hope the New Year will bring you all only joy.

As the last post of this year I thought I’d do a little progress report on bug isolation from dregs and even beers that some of you were nice enough to send me.

I think of most interest to you will be the progress of Cascade Brewing Barrel House dregs because of the Lactobacillus brevis strain that they inoculate their beers with. Even though L. brevis is commonly thought of as a hop resistant species that produces aggressive acidity in beers it isn’t exactly right and some strains of L. brevis are killed by hop acids. Genetics of lactic acid bacteria hop resistance are interesting and are not bound to a particular species, but that will be discussed in a future post, which I’m already working on. In any case let us see what’s been happening at the lab these last few weeks.

Cascade Kriek

From their website: Our Kriek spends over six months in lactic fermentation and aging in oak barrels. This NW style sour red ale is fermented for eight months with fresh whole Bing and sour pie cherries.

Those who have had it will know that it’s very sour and aggressive. Actually when I had it before I became interested in reculturing and thus just poured away the dregs, I thought my tongue and tooth enamel were dissolving with every sip. Sounds like a very good source for that particular Lactobacillus strain, doesn’t it? Luckily, ‪Ryan Wagner from KROC (Keg Ran Out Club) had a culture of it growing in his yeast ranch and was kind enough to send some during the Cantillon Brettanomyces sharing event. Per his description, the culture was maintained at practically ideal conditions for Lactobacillus maintenance and produces a clean, strong and bright lactic character in wort within just a few weeks after inoculation with flavors and smells reminiscent of apricots. It was really exciting to get my hands on this culture because it sounded very promising. Shortly after receiving the culture I streaked it on some plates and took a peak at it under microscope. It was immediately apparent that the sample is practically loaded with Brettanomyces. This was a little strange since, as far as common knowledge goes, they do not use Brett in most of their beers. I contacted Ryan the same day and he confirmed that the culture contains only whatever was raised from the Kriek dregs. After that I contacted Brandon at Embrace the Funk since he asked to keep an eye out for Brett in Cascade beers because their flavors seem too “bretty” to be just regular Saccharomyces. He was not very surprised and said that Chad Yakobson also saw Brettanomyces in Cascade beers and this confirms it. The only logical conclusion as to the origin of this yeast in the beer then would be that it’s wild and got there from the barrels or the cherries used during fermentation and aging.

Micrograph of the Cascade Kriek culture. This definitely looks like Brettanomyces to me.

Micrograph of the Cascade Kriek culture. This definitely looks like Brettanomyces to me.

After a few weeks on different agar plates I ended up with three types of colonies that you can see below in the 12-3 o’clock portion of the MYPG+BG+p-C plate. These colonies look much better on other agars, but I’ll refrain from telling you about those for now for the sake of staying on topic. One seems to be Brettanomyces – medium to large, round, glossy, convex colonies. Another looks like Saccharomyces – round, flat, and matte. Perhaps it’s just some contaminant because those are very rare. The third looks like Lactobacillus – small, irregular/filamentous, colorless/off-white/yellowish. Each organism was inoculated into a small primary culture and will be used later to raise bigger ones.

MYPGBGp-C plate with various cultures streaked in quadrants.

MYPGBGp-C plate with various cultures streaked in quadrants.

Saccharomyces?

Saccharomyces?

While looking at yeast is fairly straightforward, looking at bacteria is a lot more difficult. These organisms are a lot smaller and my usual 600x magnification doesn’t suffice at all. They are so small and there is so little to them that the light just goes straight through and around the cells, making them difficult to see and requiring some playing around with the light, the condenser and the light filters on occasion. Here you can see micrographs taken at 1500x magnification, which is 2.5 times greater than that at which I usually take yeast pictures. They still look smaller than yeast at 600x so imagine just how tiny these guys are. Staining also helps a great deal. Compare the images of unstained and methylene blue stained cells and what difference in viewing it makes.

Unstained Lactobacilli

Unstained Lactobacilli

Methylene Blue Stained Lactobacilli

Methylene Blue Stained Lactobacilli

While I was at it, I also took some high power images of the Brettanomyces from this culture and even captured a short real-time video where you can see what I think are vacuolar granules or fat globules moving inside the cells and me playing with the focal planes a little bit.

Cascade Kriek Brettanomyces

Cascade Kriek Brettanomyces

Cascade Kriek Brettanomyces

Cascade Kriek Brettanomyces

Cascade Kriek Brettanomyces

Cascade Kriek Brettanomyces

Cascade Kriek Brettanomyces

Cascade Kriek Brettanomyces

Cascade Kriek Brettanomyces

Cascade Kriek Brettanomyces

These organisms don’t seem to metabolize bromocresol green and stay as green colonies on BG-containing plates. That is not really a big deal since not all Brettanomyces species possess that ability anyway.

What is curious, though, is that the bromocresol green containing colonies did not remain blue, but turned green-yellow. There are about 4 other Brettanomyces strains on that same plate and they depleted the dye from the entire plate, but some of it stayed in the colonies. You can even see some blue colonies that did not turn green or white. Other than being a dye BG is also a pH indicator changing color from blue to yellow as it becomes more acidic, and as I discussed in the “Size Matters?” post, in aerobic conditions with available glucose Brettanomyces may produce acetic acid. The pKa of acetic acid is 4.76, which is exactly enough to turn BG green-yellow. This could also explain the yellow-green color of Lactobacillus colonies. The pKa of Lactic acid is 3.86, which is exactly at the border of where BG spectrum turns completely yellow. Of course right now it’s all just speculation.

Findings so far:

–       Cascade Kriek contains a lot of what seems to be Brettanomyces, which may account for the fruity character that results from fermenting with it. Not only does Brettanomyces produce fruity esters during fermentation, but it also produces fruity compounds during its acid breakdown as a survival action (see my “Size Matters?” post) and Lactobacillus provides plenty of acid.

–       This strain of Brettanomyces does not seem to metabolize bromocresol green.

–       The presumptive Lactobacillus cells are short and thick, which is a typical look of L. brevis. For example L. delbrueckii cells are longer. Sorry I don’t have my own images to show you for comparison because my entire L. delbrueckii stock died. Slightly off topic, but don’t keep your Lactobacillus and Brettanomyces cultures in the fridge. They seem to die surprisingly quickly in the cold and it’s better to keep them warmer and passage once in a while. But that’s for another post. Here is a nice collection of pseudocolored SEMs that you could look at for comparison, just keep in mind the scale differences (L. delbrueckii is a subspecies of L. bulgaricus.)

–       These bacteria are aerobic (another L. brevis trait) and grow much better in aerobic conditions.

–       Both organisms seem to produce acid in aerobic conditions with glucose as the carbon source.

Future directions

–       First and foremost I’ll try to test the hop resistance of these bacilli and, hopefully, confirm their beer souring ability. There seemed to be a chance to do genetic testing of that trait for a while, but I don’t think it’ll play out in the end and it’ll have to be done by a stepwise increase of IBUs in the growing medium. Luckily I saved a few hundred mL of a 120 IBU IIPA back when I brewed it and it’s been frozen for a few weeks just for that purpose.

–       Irregular shape of the presumptive Lactobacillus colonies suggests motility (ability to move), which is a trait that L. brevis is supposed to possess. For example Lactobacillus delbrueckii that is readily available from WYeast or White Labs is non-motile and forms round colonies. Just to be sure I’ll make some motility agar tubes next time I pour plates and stab them.

–       Gram stains to confirm that they are gram-positive.

–       What’s a little troubling is that these bacteria do not seem to produce acid when given lactose as the sole carbon source. Both presumptive Brettanomyces and Lactobacillus grow very happily on lactose, though not as quickly as on glucose, but do not produce any acid. Perhaps anaerobic conditions are required and I’ve already put them into an anaerobic chamber to see what happens.

–       The seeming acid production from glucose seems intriguing and will have to be done in liquid cultures with proper pH measurements and indicators.

Sounds exciting, doesn’t it? I’m curious to see what results will turn up from this little study.

The Kriek culture is just one of the few that you guys sent me to analyze and each one deserves attention and work. Sounds like a busy year already! Thanks again to all my readers for your support, collaborations and yeast trades and I wish you well. Some of you, however, didn’t send the cultures that you promised or stiffed me on the shipment costs, and for that may your beers be infected and not in a good way!

Happy Holidays!

Size Matters?

Thoughts on cell size, counts, pitching rates and characteristics of Saccharomyces and Brettanomyces

 

It’s no secret to anyone by now that the amount of yeast pitched into wort plays a major role in the resulting beer. It affects the fermentation onset, progression, alcohol production, and overall flavor characteristics of the finished product. Pitch too little and fermentation may not complete to the degree desired, yeast may stress out and release compounds that cause flavor and aroma flaws, and the beer overall may just turn out “weird.” Pitch too much and your beer will not have the flavors and aromatics desired and just be “too clean.” Both these scenarios may be seen as problematic for the brewer. While over-pitching is not such a big concern on a homebrew level unless you decide to ferment a mild on a full cake from a Russian Imperial Stout (RIS), under-pitching is an all-too-common occurrence. The wealth of information available on the subject is quite abundant and there aren’t that many people left who are unfamiliar with the concept. But how does one go about determining proper pitching rates?

First, let’s do a quick review of the yeast math. The general consensus based on calculations by Dr. George Fix seems to be 0.75-1 million cells per mL of wort per ⁰P for ales and 1.5-2 for lagers. The famous MrMalty’s calculator uses values of 0.75 and 1.5 for ales and lagers, respectively (Mr. Malty). For the sake of simplicity, lets work with values of one and two million for our subsequent calculations. If our OG is 1.050 (12.4 ⁰P) and there are approximately 20,000 mL in 5.25 Gal, the calculation would go like this:

1,000,000 cells X 12.4⁰P X 20,000mL = 248,000,000,000 => 248 Billion cells.

Repeating the same calculation for lagers would give us 496 Billion cells.

For those of us who use the specific gravity system (myself included), a quick review of the Plato scale may be in order. Developed in 1843 by Karl Balling and Simon Ack, and later improved by Fritz Plato, Plato scale measures density of wort as a percentage of extract by weight. As a reference it utilizes sucrose and its solubility in water. Therefore Plato density is correlated to percentage of sucrose in solution by weight. For example 15⁰P is equivalent in density to a 15% solution of sucrose, known as 15% Brix (°Bx) in wine industry (Wikipedia). Degrees Plato are also often expressed as OE for “Original Extract” (Wikipedia). To convert between ⁰P and SG one may utilize a simple formula ⁰P = SG/4. For example 12 = 1.048/4. This formula begins to fail around SG 1.050 and deviates further after 1.060 due to the fact that the exact correlation between the two systems is not linear. A more exact formula would be ⁰P = 259-(259/SG) and offer a greater accuracy of conversion. This deviation from linearity is caused by the fact that the final wort volume is greater than that of the water used to make it due to solubilizing of sugars constituting it (Troester, 2012). Each system has its advantages and Plato is more popular in Central European brewing industry while SG is more common in the homebrewing culture in Americas and countries from whom we inherited most of our brewing traditions, namely Great Britain. Professional brewers, however, prefer Plato. Personally I find SG easier and more intuitive to use, but by no means is one better than other.

Let us continue. Why is the demand for cell numbers twice as high in lagers as it is in ales? I believe it is due to the conditions of fermentation as well as nature of lager yeast – Saccharomyces pastorianus. S. pastorianus is a close relative of S. cerevisiae and S. bayanus and is believed to be a hybrid of the two due to a large number of similarities and overlaps between the species. These include the ability to metabolize melibiose – trait exclusive to very few yeasts such as S. bayanus, mitochondrial and ribosomal DNA also seems to be S. bayanus-derived, inability to grow in temperatures as high as S. cerevisiae is able to tolerate (think about Saison yeast) and faster proliferation at low temperatures than that of S. cerevisiae (Wikipedia). S. pastorianus has been shown to possess three types of chromosomes: 1) chromosomes from S. cerevisiae; 2) chromosomes from S. bayanus; 3) recombinant chromosomes from both species (Nakao, et al. 2009; Tamai, et al. 1998; Querol and Bond. 2009). In my search on the topic I could not come up with anything concrete in terms of cell number requirements so my opinion is that the temperature and cell size are the main deciding factors. Metabolic processes are slower and more yeast are needed to process through the wort in a timely fashion without population stress (same story as with underpitched ales) that may result in off flavors and other flaws such as incomplete fermentation. One more thing to look at is the fermentative nature of this yeast. Since they stay at the bottom over the course of beer fermentation, they do no move through it as much as ale yeast that float up to the top and go down and up and thus there is a lot more contact between the beer and yeast in an ale than lager. Another issue is cell size. There are reports floating around the web about lager yeast cell being smaller than ale ones. To confirm this I looked at WY2206 Bavarian Lager and the results are that these cells are indeed about 1.5-2 times smaller than US-05 (see below). It stands to reason then that each cell can only handle a fraction of the metabolic load that an average S. cerevisiae cell can and thus more cells are needed to process the wort.

On to Brettanomyces – the favorite yeast of majority of this blog’s readers! Now I’ve said it a hundred times before, but I’ll say it again. Brett is yeast and not bacteria. I’ve been to beer presentations and meetings where speakers call them bacteria, I’ve met and talked to homebrewers who think Brett are bacteria and I’ve read stuff online calling them bacteria. This misunderstanding is probably caused by lack of biological education among most brewers and beer aficionados, and that’s OK. That’s why blogs like this one exist. Yeast are eukaryotes which means they have nucleus and complex organelles enclosed within membranes, while bacteria are prokaryotes which means they do not have these structures and their genome is not enclosed within a nucleus. Bacteria are a lot simpler in terms of cellular and genetic structure and are about 1/10 the size of an average yeast cell or smaller. Yeast belongs to the fungi kingdom, which means they are neither plants nor animals, but their own separate kingdom of living creatures and are cousins of mushrooms.

Now that we are clear about that, let’s talk about some history and characteristics of Brettanomyces. The first strain of Brettanomyces was characterized in 1904 by N. H. Claussen, who isolated it from an old English stock beer (Gilliland 1961). The name Brettanomyces is derived from “British fungus” because the flavors produced by it were typical of British beers at that time. In 1940s M. T. J. Custers did a systematic study of this yeast and found its association with wine (Custers 1940). Over the years the taxonomy of the genus underwent several revisions and initially consisted of five strains: Brettanomyces bruxellensis, Brettanomyces lambicus, Brettanomyces clausenii, Brettanomyces anomalus and Brettanomyces intermedius, which reproduced asexually by budding (Custers, 1940; Van der Walt & Van Kerken, 1958). In 1964 production of ascospores was noted and genus Dekkera was introduced into the classification to denote spore-forming Brettanomyces species (Van deer Walt 1984). Importance of this discovery was that Brettanomyces are able to reproduce sexually and not only by budding, introducing a much greater genetic variability. Currently the Brettanomyces/Dekkera genus contains five species: Brettanomyces custersianus, Brettanomyces naardenensis, Brettanomyces nanus, Brettanomyces anomalus and Brettanomyces bruxellensis (Kurtzman & Fell, 2000; Cocolin et al., 2004). The last two also exist as telomorphs (sexually reproducing, spore forming forms) and are known as Dekkera anomala and Dekkera bruxellensis, respectively (Kurtzman & Fell, 2000). Strains popular among brewers such as B. lambicus and B. clausenii officially now belong to and are subspecies of B. bruxellensis and B. anomalus, respectively. This means that the trademarked names sold by the yeast companies may not accurately reflect the taxonomical classification of these yeasts. There has been a surge of interest in Brettanomyces research in recent years and their morphological, physiological and biochemical characteristic have been studied in depth. Currently there is an argument whether or not it is wise to keep the distinction between Brettanomyces and Dekkera as there seems to be no DNA distinction between the anamorphic and telomorphic forms (Loureiro & Malfeito-Ferreira, 2006). This is also influenced by the fact that most, if not all, of these studies are paid for by the winemaking industry as Brettanomyces bruxellensis is a major contaminant in red wine with Brettanomyces anomalus playing a lesser role and the Dekkera form is not observed in fermenting wine.

Other than wine, Brettanomyces also plays a role in fermentation of cheese and other dairy fermentation products, beer, cider, kombucha and tequila. It has been found on grapes, bees, fruit flies and even olives (Van der Walt & Van Kerken, 1958; Phaff et al., 1978; Deák & Beuchat, 1995; Kotzekidou et al., 1997). It has also recently surfaced as a major contaminant in biofuel production where it actually grows strong enough to compete with other yeast. This robust fermentative capacity of that particular strain sparked an interest in possibility of utilizing it for biofuel production and to the best of my knowledge there is research being done in this direction. Since all this research is done in wine context, I’ll try to draw parallels to beer fermentation and aging. During normal wine and beer fermentation Brettanomyces is generally associated with aging as they are easily outcompeted by other rapidly fermenting yeast. During aging and cellaring, however, their numbers increase due to more favorable conditions after the end of alcoholic fermentation that suits their slow growing characteristics by providing them with traces of residual sugars (Fugelsang et al., 1993). Unlike wine makers, brewers do not use sulfur dioxide during aging and cellaring therefore beer is a much more welcoming environment for Brettanomyces. As beer ages there is very little microbial competition, low residual sugar content and cell autolysis that releases plenty of nutrients. Of particular benefit for Brettanomyces are wooden barrels, which, due to their porous structure, allow oxygen to slowly seep into the beer as well as present them with cellobiose, which is a sugar they can utilize (Boulton et al., 1996). It is also all but impossible to sanitize wood so once a colony establishes itself it’s there to stay (Oelofse et al., 2008). A number of selective media for Brettanomyces isolation and growth have been developed over the last 50 or so years with varying degrees of efficiency and there are nice examples of them available at Chad Yakobson’s Brettanomyces Project web resource.

Production of volatile phenols by this yeast is what winemakers are afraid of and what funky brewers are embracing. These phenols are a large family of aromatic compounds with vinyl- and ethylphenols being the main culprits of the horse, leather, sweat, barnyard and spicy characteristics that we all know and love (Chatonnet et al., 1992; 1995; Suárez et al., 2007). Phenol production occurs as a survival response in an increasingly acidic environment. Brettanomyces convert various acids that are produced during fermentation or present in fruit (think of all the fruit sour beers) into volatile phenols to survive in the increasingly toxic environment while we reap the benefits of the resulting funky complexity of these chemicals. Enzymes and mechanisms of phenol production have been well studied and are way over average homebrewer’s level. These yeast are also known for their ability to generate acetic acid and impart vinegary characteristics to beer and wine (Van der Walt & Van Kerken, 1958). Acetic acid production occurs in presence of oxygen and requires glucose as starting material. Even if there is glucose available, but no oxygen, they will not perform acetic fermentation (Licker et al. 1998). It should be noted that not all Brettanomyces species produce acetic acid. For example B. naardenensis and B. nanus do not and this property can be used as a selective marker to distinguish between strains. However these strains are not important in brewing and aren’t seen very often. A very popular myth in brewing world is that Brettanomyces and other yeast and bacteria form a pellicle on top of the beer surface to protect the beer from air. That is a complete nonsense since they couldn’t care less if your beer is oxidized or not and what it tastes like. They simply like to hang around there due to availability of oxygen and in doing so make a complex matrix called pellicle where yeast and bacteria often work together to a mutual benefit.

There are also a number of other compounds and acids produced which account for various flavors and aromas such as mouse, popcorn, metallic, pineapple, apricot etc with ethanol being a precursor for many of them, but further elaboration of their production is probably unnecessary. In recent years the use of Brettanomyces as the main fermenting organism in beer it has gained noticeable popularity. Since this practice is so new there has been virtually no research done on their biology in such uncompetative conditions. The only thing we know for sure at this point is that when there is no microbial competition they behave very similar to Saccharomyces and produce clean and fruity beers. The pioneers in this movement recommend lager-pitching rates for all-Brett ales and it sparked my curiosity and eventually lead to creation of this article. All in all beer microbiology is an extremely complex subject and one lifetime isn’t enough to study it. There are many strains within each species, each with their unique characteristics same as with Saccharomyces. As a food for thought for all you Brett junkies out there, I recently read a paper on metabolic assay of dozens of B. bruxellensis strains and some of them do well at lager temperatures while others have incredible alcohol tolerances. Could we see all-Brett lagers and imperial brews in coming years?

In my home lab I decided to look at cell size of the Brettanomyces C3 isolate and compare to US-05. The resulting figure below illustrates the difference between the yeast types mentioned above in terms of their size.

Yeast Cell Size Comparison: A) US-05, B) WY2206, C) Brettanomyces C3 Cantillon Iris (2007) Isolate, D) Chart comparing average cell diameters based on the micrographs shown. Cells that were oblong rather than round were measured at approximately 45 degree incline relative to the midsection to approximate circular diameter. Micrographs were taken at 600x magnification. Processing and measurement was done using specialized software and calibrated using a 0.01mm scale calibration slide. Error bars reflect standard error.

As you can see Brettanomyces cells are up to 3 times smaller than the normal ale strain cells. Such size difference may very well account for the higher pitching rates required in all-Brett fermentations (same rationale as for lagers, see above). I’d even go as far as recommend doubling or even tripling the pitch rate for the C3 strain that a lot of you are currently playing with. From my personal experience with this yeast I can tell you that underpitching results in buttery/popcorn flavors that slowly diminish over time. Could be dactyl, or it could be one of the aromatic compounds they produce. Beer currently fermenting on top of that underpitched beer’s cake still emits very sweet overripe pineapple and mango aromas through the airlock for about 5 weeks now.

Let’s look a little bit at cell volumes. Assuming we can project these data and assume the cells may be thought of as spheres based on an average diameter, their average volumes would be 455, 82 and 22 μm3 for US-05, WY2206 and Brettanomyces C3, respectively. This implies that there is a 20-fold difference in the cell volumes between US-05 and Brett C3 and 5-fold between US-05 and WY2206. Just imagine how many more cells would be there in the same volume of sediment! We’ll come back to this topic and its implications a little bit later in this article.

An interesting point was brought up during the review of this article in regard to cell size changing between fresh pack from WYeast and after they have had a chance to ferment. To address that, I compared WY2206 fresh from a pack and after 5 days in liquid culture (DME-based starter). Resulting sizes did not differ significantly (0.2 µm) and so I conclude that the size does not significantly differ between packed and active yeast.

It should be pointed out that the measurements presented here are only pertinent to these particular yeast strains. While it looks like the sizes of various Brettanomyces spp. species and S. pastorianus strains are around the same as shown here, there is evidence that there may be a significant fluctuation in sizes between S. cerevisiae strains (unpublished data). I theorize that US-05 is a robust strain, which is able to survive the harsh conditions of dry preservation that, as I’m sure you all know, is lethal to most other yeast strains. This could be in part due to their size, which may be bigger than other “liquid culture yeasts” such as the ones you may buy from WYeast or White Labs. This issue will be addressed in future posts in collaboration with Sam at Eureka Brewing. We’re already working on it so look out for that in the upcoming weeks.

Now that that’s a little bit cleared up, what are some of the common ways to measure cell numbers?

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Following has beed adapted from Dr. David Wartell

Direct Counting Measures: Give us very precise numbers.

Microscopic Counting:

– Special Slide (cell counter/hemocytometer) with grids of known volume.

– Count cells and convert them to cells per mL.

– Can’t differentiate viable cells from dead ones unless vital stains are used.

Electronic Counting:

– Coulter Counter: cells pass through an electrical current and interrupt it. The interruptions are noted and converted into cell counts.

– Flow Cytometer: cells pass through light path and are counted. Similar to Coulter.

– Neither gives viable cell count.

Standard Plate Count (SPC):

– Cells are diluted through a serial dilution and a known volume is plated.

– Each colony on a plate corresponds to a single viable cell originally plated – colony forming units (CFU).

– Gives a viable cell count. Based on the number of colonies resulting from the known volume plated, the original viable cell count may be calculated. For example: A million fold dilution was made and 100µL (microliters, 1µL = 1/1,000mL so 100µL = 0.1mL) of it was plated and gave rise to 50 colonies. Thus the original live cell count was: 50 colonies X 1,000,000 fold dilution / 0.1mL = 500,000,000 cells per mL. If this was a 1-liter starter, multiply this by 1,000 and you’ll get 500 billion cells in that starter.

– Disadvantage: takes time for the colonies to grow (at least a few days). Possibility for errors when making dilutions

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Indirect Counting Measures: Do not give exact numbers, but rather estimate them by indirect means. There is a large room for error in all these methods.

 Metabolic Activity Assay:

– Known metabolic rate of the organisms. Assumes it is known how fast the cells metabolize nutrients, produce waste products, affect pH of the environment they’re in.

– Measuring the concentration of nutrients, waste, and pH changes in the culture and based on the observation approximate cell count is calculated.

Dry Weight:

– Filter culture through a filter paper, dry and weigh it.

– Estimate the number of cells from the change in weight.

– Must know approximate average weight of the cells.

Turbidity:

– Very commonly used in microbiology labs

– As the cells multiply the medium becomes cloudier.

– Changes in turbidity are measured by a spectrophotometer. This instrument measures the amount of light passing through culture. Inversely proportional to the culture density. That is the more cells are there the less light passes through.

– Drawback would be that if one strain has a different cell size than another, the absorption plots would be different for each such strain.

Volume:

– Possibly more appealing to an average homebrewer.

– Number of cells estimated based on the proportion of the yeast sediment volume to the total volume.

– Assumes approximate average size and volume of the cells in the given culture is known introducing room for a significant error.

– Sedimentation time and temperature are also important factors. Some strains flocculate better than other and bigger cells fall out faster than smaller ones, thus introducing a possibility for an error. Centrifugation may be used to solve this, but it probably isn’t an attractive approach for homebrewers. Cold passive sedimentation is probably better.

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            Of the techniques listed above three are readily available to homebrewers: microscopic counting by the use of hemocytometer, dry weight, and volume estimation. Lets begin with the least costly and least reliable and move towards the gold standard.

          Volume Estimation: WYeast offers a beautiful guide as to how to do this here and I do not think it is necessary for me to elaborate on the topic beyond their explanation (WYeast Laboratories). Just one point – their instructions are true for average ale yeast. Lager strains as well as Brettanomyces will not conform to this convention due to their smaller cell size as shown above, so there would be several times more cells in the same volume, respectively.

          Dry weight: Usually this technique is performed with the entire culture, but for a brewer drying out the whole starter would not result in anything good so let’s look at a different approach. It is quite easy to raise a culture of your favorite strain and make a number of dilutions such as 1-5-10-20-50-100 million cells per mL, then take 1mL of this and put it on a piece of pre-weighed filter paper, napkin, or a piece of paper towel. Allow it to dry either passively or by putting it near a heat source to speed up the process. After it is dry, measure the weight and compare to what it used to be before. Repeat it a few times for each dilution to obtain an average weight. This way you could easily construct a graph that will give you a cell to weight ratio and plot into which your latter measurements may be fitted and allow you to project your starter density easily. Drawbacks of this method would of course be inability to distinguish between living and dead cells, as well as requirement for a microscope and hemocytometer at the initial stage to make the initial counts and dilutions. One would also need precise balance able to measure to fractions of a gram, but most homebrew stores carry them these days. Kai Troester at Braukaiser utilizes an approach similar to this. His approach is through a total weight of the entire wet culture. While the weight of the flask and stirrer are known and don’t change and so are not unknown factors, the volume of the actual slurry is. This results in a variable density of the culture from batch to batch and introduces room for error especially with low flocculating strains. It is a good and useful approach nonetheless and errors are within reasonable bounds (Troester, 2012).

          Microscopic counting: I’m absolutely sure that every brewer who has ever heard of yeast cell counts is familiar with this method. There are endless articles, posts, how-to etc all over the net and there is no need to me to reiterate this. It is the best method utilized by everyone who wants precise and fast results. If you do want to refresh your memory, Kai wrote a marvelous article about counting here (Troester, 2012). He also goes over methylene blue staining, which is widely used for purposes of assessing yeast viability. Dead cells stain blue, living ones do not because it turns colorless in the living cytoplasm, and it works to a certain degree. Those of us who are a little familiar with this stain also know that it often gives false results and sometimes introduces a significant error in viability estimations because it scavenges the hydrogen atoms and inhibits yeast respiration. In my opinion trypan blue, which works on a principle of cell membrane integrity, is a lot better, but there is a drawback. It’s out of reach for most homebrewers and it’s also expensive. You can probably buy about half a liter of methylene blue solution for the price of a vial of trypan. I’ve been reading some literature on other vital stains that could be used by homebrewers and came across Phenol Red and Neutral Red that work by changing color inside the cells due to pH difference between the cytoplasm and outside environment. However my experiments with those stains did not yield any results yet. If anything useful comes from it, I’ll write about it.

There is also a possibility to do a Metabolic Activity Assay on a homebrew level. It would be necessary to do a thorough analysis of each yeast strain and population vs fermentation curves should be thoroughly analyzed.

To conclude this article, let’s reiterate the main points:

–       Pitching the right number of yeast cell into your beer is important for a proper and complete fermentation.

–       Lager yeast cells are not the same as ale yeast in terms of both size and species.

–       Brettanomyces are a very different yeast species with very different characteristics and their cells are considerably smaller than average ale yeast.

–       Since these cells are so much smaller, it is necessary to pitch at least twice the regular number of cells into your wort for fermentation to proceed normally if you’re doing pure strain fermentation.

–       Conditions of stress and low nutrition are required for Brettanomyces to produce their funk. This should not be mistaken with fermentative stress such as what may occur in underpitched wort. Underpitching would create high nutrition environment and stress conditions and would result in much similar outcomes as underpitching your regular brew. Post-fermentation environment with its low nutrition, trace sugars, acidity, acids, alcohols and other byproducts is what’s needed for the funky processes to happen. Byproducts released by Saccharomyces cerevisiae species during fermentation can be and are utilized by Brettanomyces spp. in a cofermentative environment, resulting in funk as well when the wort is inoculated by both species from the start.

–       Oxygen is needed for acetic acid as well as some other funk production by Brettanomyces.

–       Brettanomyces can utilize sugars from wood to survive and also hang around its surface as well as surface of the beer (forming the well known pellicle phenomenon) because there is oxygen there. However not all species can form a pellicle on their own.

–       Brettanomyces aren’t some evil creatures with an aim to spoil your beer, but rather a wonderful family of organisms with a fascinating biology and their contributions to the brewing world are nothing short of marvelous.

–       Brettanomyces fermentation is an area of active research that hides many secrets.

–       There are various techniques available even to homebrewers allowing estimating or obtaining a precise cell density.

I hope you enjoyed reading this this article as much as I did putting it together and it was helpful to you in one way or another.

Acknowledgments:

I’m very grateful to people who reviewed this work:

Samuel Aeschlimann of Eureka Brewing – my friend and brother in arms in both homebrewing and science, whose comments and remarks were very helpful and lead to prolonged discussions and raised a number of interesting questions. Look for a series of collaborative scientific posts with him in the near future.

Dr. Tom Schmidlin – a scientist and a homebrewer whose comments and remarks were very helpful.

Kai Troester of braukaiser.com – a homebrewer and experimenter whose work is quite interesting and serves the benefit of homebrewing community, for his expertise in Plato system as well as comments regarding yeast.

Brandon Jones of EmbraceTheFunk – a funk missionary who endlessly works to spread the funk around, for his helpful comments and questions.

References:

Boulton, R.B., Singleton, V., Bisson, L.F. & Kunkee, R., 1996. Principles and Practices of Winemaking. Chapman & Hall Publishers New York, NY.

Chatonnet, P., Dubourdieu, D. & Boidron, J.N., 1995. The influence of Brettanomyces/Dekkera sp. yeasts and lactic acid bacteria on the ethylphenol content of red wines. Am. J. Enol. Vitic. 46, 463-468.

Chatonnet, P., Dubourdieu, D., Boidron, J. & Pons, M., 1992. The origin of ethylphenols in wines. J. Sci. Food Agric. 60, 165–178.

Cocolin, L., Rantsiou, K., Iacumin, L., Zironi, R. & Comi, G., 2004. Molecular detection and identification of Brettanomyces/Dekkera bruxellensis and Brettanomyces/Dekkera anomalus in spoiled wines. Appl. Environ. Microbiol. 70, 1347–1355.

Custers, M.T.J., 1940. Onderzoekingen over het gistgeslacht Brettanomyces. PhD Thesis, Delft University Delft, The Netherlands.

Deák, T. & Beuchat, D.R., 1995. Modified indirect conductimetric technique for detecting low populations of yeast in beverage concentrates and carbonated beverages. Food Microbiol. 12, 165-172.

Degrees Plato to Specific Gravity Conversion. <http://www.winning-homebrew.com/Plato-to-specific-gravity.html&gt;

Fugelsang, K.C., Osborn, M.M. & Muller, C.J., 1993. Brettanomyces and Dekkera. Implications in winemaking. In: Gump, B.H. (ed). Beer and wine production: analysis, characterization and technological advances. American Chemical Society, Washington DC, pp. 110-131.

Kotzekidou, P., 1997. Identification of yeasts from black olives in rapid systems microtitre plates. Food Microbiol. 14, 609-616.

Kurtzman, C.P. & Fell, J.W., 2000. (4th ed. revised). The yeasts. A taxonomic study. Elsevier Science Publisher BV, Amsterdam, The Netherlands.

Licker, J.L., Acree, T.E. & Henick-Kling, T., 1998. What is ‘‘Brett’’ (Brettanomyces) flavour? A preliminary investigation. In: Waterhouse, A.L. & Ebeler, S.E. (eds). Chemistry of wine flavour. ACS symposium series. Am. Chem. Soc., Washington, DC, pp. 96-115.

Loureiro, V. & Malfeito-Ferreira, M., 2006. Dekkera/Brettanomyces spp. Chapter 13. In: Blackburn, C. de W. (ed). Food spoilage microorganisms. Woodhead Publishing Ltd, Abington, Cambridge, UK. pp. 353-398.

Mr. Malty. Proper Yeast Pitching Rates <http://www.mrmalty.com/pitching.php&gt;

Nakao, Y.; Kanamori, T.; Itoh, T.; Kodama, Y.; Rainieri, S.; Nakamura, N.; Shimonaga, T.; Hattori, M.; Ashikari, T. Genome sequence of the lager brewing yeast, an interspecies hybrid. DNA Res. 2009, 16, 115-129.

Oelofse, A.; Pretorius, I.S. and du Toit, M. Significance of Brettanomyces and Dekkera during Winemaking: A Synoptic Review. S. Afr. J. Enol. Vitic., Vol. 29, No. 2, 2008. 128-144.

Phaff, H.J., Miller, M.W. & Mrak, E.M. 1978 (2nd ed). The Life of Yeasts. Harvard University Press, Cambridge, MA, p. 341.

Querol, A.; Bond, U. The complex and dynamic genomes of industrial yeasts. FEMS Microbiol. Lett. 2009, 293, 1-10.

Suárez, R., Suárez-Lepe, J.A., Morata, A. & Calderón, F., 2007. The production of ethylphenols in wine by yeasts of the genera Brettanomyces and Dekkera: A review. Food Chem. 102, 10-21.

Tamai, Y.; Momma, T.; Yoshimoto, H.; Kaneko, Y. Coexistence of two types of chromosome in the bottom fermenting yeast, Saccharomyces pastorianus. Yeast 1998, 14, 923-933.

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Troubadour Tasting

It’s time to finally do an official Raspberry Berliner tasting!

In the aftermath of the disastrous hurricane Sandy that stormed through the eastern seaboard it’s nice to have something as simple and comforting as a glass of good brew. During the storm I lost power for some time, cell network, hot water and heat, but now everything is fine and I’m back to brewing and drinking. It should probably be mentioned that this bottle is the only 750mL bottle of Troubadour that escaped the storm unscathed thanks to being in the fridge. All others, along with plain Berliner, Witch Poison Gruit, Mead and others were in a basement that got flooded and I didn’t think anything survived in there after seeing the complete destruction that the flood caused. This morning I went down there with a flashlight and waded my way through water, mud, silt, broken furniture, destroyed boxes and so on in search for my beer and some lab equipment I was keeping there. After seeing annihilated shelves and chairs hanging from the ceiling (water rose higher than the basement sealing) I didn’t have much hope, but luckily all my beers and mead escaped unharmed and were only covered in silt! I was able to recover everything I hoped to find there in good condition.

Anyway, let’s get down to it!

I’ve only tasted this beer once before this summer when I brought it to a homebrew meetup and it was well received and I liked it more than the plain version. Not a single bottle had been opened since then so it was a bit of a special experience opening this one. Since my family is celebrating my birthday tonight (it’s actually tomorrow, but everyone is busy) it was a nice addition to the evening.

Appearance: Brilliant, crystal clear. Orange-pink color. Lots of bubbles. Head rises and quickly falls into a ring around the glass that persists throughout the tasting.

Smell: Bright, acidic, very similar to the plain version but with a pronounced raspberry instead of champagne aroma. Funky. Sour. Delicious!

Taste: Lactic sourness up front, but very gentle, just how I like it. Funk from the nose carries into the flavor and takes over. Raspberry pokes out here and there but is not the main player. It’s there, but in the back seat playing along with everything else that’s going on. Possibly very light, almost unnoticeable acetic note. Slightly musty. No malt noticeable. Mouthwatering tart finish. Vinous.

Mouthfeel: Very light but with so much flavor!

Overall: I impressed myself with this beer. Amazing how something so simple turned out so tasty. I am determined to get back into that basement and rescue my 15 Gal fermentors to get the next batch of Berliner going as soon as I can do it!