Plates Plates Plates

The plates finally arrived today and I decided to go ahead and pour 10 Malt agar and 10 Potato Sucrose just as a trial run. Now I’ve made a ton of plates in the lab before, but never in my kitchen. Everything went well except that for some reason the agar ended up too soft (used the usual 1.5g per 100mL ratio.) Regardless of it turning out the way it did I went ahead and streaked a couple cultures just to see if anything grows or not. One of them is the WY Berliner Blend and another one came from a bottle of a brew from a small Belgian brewery that produces very soft and bright fruit/cotton candy/bubblegum character without the sweetness. The agar scratched (stop hatin’!) but I’m optimistic about being able to pick out colonies. For the next batch I’ll bump up the agar concentration and get a decent blow torch to get rid of bubbles, which weren’t a problem today, but it never hurts to be prepared. Btw I have 500 more plates so plenty of opportunities to try out different things 🙂

You can't do any homebrew science without some homebrew, right? This is my lemongrass and spearmint braggot. After cold conditioning for a couple weeks it cleared up and mellowed out very nicely. Tasty stuff!

Talk about flash reflection!

You can see the scratches very well in this shot. Pity... I'll have to repeat this whole thing with normal density agar anyway.

 

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Staining The Berliner Weisse

So over the weekend I decided to try staining some samples from my Berliner Weisse carboys. What I really wanted to see was how gram staining would affect the ascospore visibility as I read that the spores themselves would appear negative while the vegetative cell would be positive. I also wanted to try Methylene Blue and Eosin Y stains just to see what the Brettanomyces and whatever else is there would look like. Sounds exciting, right?

The results, however, were disappointing:

First, the cells shrunk due to heat fixation.

Second, the sample quality was horrible. I don’t know why, but all four slides looked bad and there was barely anything worth looking at.

Third, as a result, the pictures I took also looked horrible.

Fourth, I really couldn’t find any Saccharomyces in the Raspberry Berliner. It’s been barely a week since I stirred up the cake and it seems that there really isn’t anything left for them to ferment because they all appear to have just dropped down to the bottom like a rock. Some Brett came up though and is hanging around the top.

What is really encouraging is that I did not see any Acetobacter. Now I haven’t looked at a pure culture, but I know they’re gram negative and relatively big. I’m a bit paranoid about this no boil brew turning vinegary on me as it’s something I just CAN’T STAND in my beer. There are hints of vinegar in the taste that are most likely contributed by the Brettanomyces, and that OK. Just so long as I don’t end up popping open a bottle of malt vinegar in a year. Anyway, I didn’t see any gram negative bacteria that resemble Acetobacter to me. In fact, I couldn’t see any gram negatives there and that is generally a good thing since they tend to be not the friendliest of microorganisms. There were some gram positives that looked like they could be Lactobacilli which is expected and encouraged in this style.

Anyway, the pictures are horrible, and I haven’t actually stained a sample in something like 6 years since I kind of work in a slightly different direction. Hopefully my technique will get better with time, resulting in better quality pictures.

Gram stain of the plain Berliner. You can see the Brett, some Sacch, and what looks like Lacto.

Methylene Blue and Eosin Y stain of the plain Berliner. Didn't come out how I expected and nothing really interesting showing up here. You can see some Brett

Methylene Blue and Eosin Y stain of Raspberry Berliner. A group of some bacteria, possibly Lacto.

Looking at WYeast Berliner Weisse Brettanomyces and Saccharomyces

On April 10, 2011, I made a 15 gal batch of Berliner. Never really thought of making this style until the friendly folks at Brooklyn Homebrew gave me a couple old WYeast 3191, and since this one requires no boil I went ahead and made a big batch.

As per WYeast description “This blend includes a German ale strain with low ester formation and a dry, crisp finish. The Lactobacillus included produces moderate levels of acidity. The unique Brettanomyces strain imparts a critical earthy characteristic that is indicative of a true Berliner Weisse. When this blend is used, expect a slow start to fermentation as the yeast and bacteria in the blend is balanced to allow proper acid production. It generally requires 3-6 months of aging to fully develop flavor characteristics. Use this blend with worts containing extremely low hopping rates.”

The first 5 gal were kegged and consumed in about a month and it was tart and refreshing for sure. The remaining 10 were split in half. One went on top of a can of Oregon Raspberry puree (in spirit of the fact that it is often consumed with Raspberry syrup), and the other was just left as is. Pellicles came and went, and the beers got funky and clear.

Today I noticed that the pellicle is back on the plain one and since my home lab is almost set up, I decided to take a look at it.

As you can see, a certain organism dominates the composition of the pellicle. Based on the size and shape it isn’t Saccharomyces cerevisiae nor is it Lactobacilli (the pellicle looks different), and it sure doesn’t look like Acetobacter to me. This leaves only Brettanomyces unless some organism from the grain managed to thrive and overtake everything else in the brew which is not very likely IMO.

There are a number of other organisms present as well. Tiny motile bacteria are slithering around, a few round yeast cells (most likely Saccharomyces) have been observed, and it just looks like a very “lively and wild” beer.

Since I was at it, I decided to swirl up the raspberries with a racking cane in the other half just to make sure all the fruity goodness gets into the final beer as well as take a look at it under microscope. The pellicle on that one is long since gone so I expected to see a lot of Brett at the bottom. Not so! By far the major organism down there was Saccharomyces and quite a few of them were budding. This is unexpected. The beer has the same funk as it’s brother, but with a definite raspberry presence.

You can see yeast budding on top and on the right. The long filaments are the raspberries. Some bacteria in there as well.

It is also VERY interesting to see ascospore formation in Saccharomyces. I have never seen them with my eyes before today and actually didn’t even realize what I was looking at. For those who don’t know, this is another way of yeast reproduction. Haha! Bet you thought yeast reproduces by budding, right? Well this is the “post budding” stage when the cell produces 4 or 8 copies of its chromosomes and packages them into these spores. These spores can later develop into new yeast. I don’t know much about this as I am not a mycologist so if anyone out there knows about this, feel free to share.

You can see them really well in this micrograph

Pretty cool huh?

WY3191 seems like a solid limited release blend liked by everyone who tried it. Since it is only available about once every other year, I feel very good about the fact that I saved 10mL of the original in my fridge. As soon as I finish my setup (or at least the current stage of it) I’m going to take a look at it, plate, and reculture the Sacch, Brett, and Lacto. As for the beers, I’ll give the plain version 2 more weeks before bottling, and maybe a month or two to the other one for everything to settle down again.