This page will include the ongoing and past experiments.

Vital Dyes:

Dyeing Yeast Cells: Life vs Death

Dry Yeast Rehydration:

More on Yeast Rehydration

My thoughts and procedures on yeast rehydration

Home Made Yeast Extract:

Making yeast extract at home? Sounds intimidating, but it can be done!

Here is how I prepared mine.

Here are my thought on it.

Wild Yeast Hunt:

I’ve recently started trying to isolate organisms from commercial sour beers. Stay tuned for more information on the progress!

New Glarus Crabnic: As far as I could tell only Saccharomyces grew. Going to have to try again some time.

New Glarus Berliner Weisse: Alas! Couldn’t catch anything useful, but I’ll give it another go in the future.

Cantillon Iris (2007): 3 yeast strains isolated.

Vanberg & DeWulf Lambickx:

Ithaca White Gold:

Differential Media Experiments:

I am currently working on making up some agars that are inexpensive, easy to make, and will allow for easy plate making as well as differentiation between organisms.

Potato Based Media: These media are made from potatoes and are probably the cheapest and most user friendly kind out there.

Potato Sucrose Agar – Pretty much perfect medium on a home budget for general use i.e. streaking or leaving outside for a time to see what yeast and bacteria live in Brooklyn air. This may also be used with addition of Bromocresol Green to help with Brettanomyces differentiation as they are able to break that dye.

Potato Dextrose Agar – Classic potato agar that’s perfect for growing just about anything.

Potato Dextrose Agar with Litmus – Same as your usual Potato Dextrose but with addition of litmus as a pH indicator to differentiate for acidogenic organisms.

Potato Lactose Agar – Excellent for growing Lactobacillus and lactose fermenting Brettanomyces strains.

Potato Maltodextrin Agar – Potato base with maltodextrin as the main carbon source.

Milk Based Media: These media are based on milk and are perfect for culturing lactic bacteria and other organisms.

Milk Lactose Agar – with varying pH indicators to select for acid production and/or lactose fermentation typical of Brettanomyces, Lactobacilli, Pediococci, and other wild organisms. More advanced and expensive, but should be interesting and fun.

Litmus Milk Agar – Milk agar with Litmus as a pH indicator to differentiate for acidogenic organisms.


Brilliant Green Agar – home made version of this highly differential medium that inhibits gram positive and majority of gram negative bacteria allowing for isolation of Salmonella (not applicable to us homebrewers) and allowing yeast to grow. Could be used for yeast separation from lambic dregs.

There are hundreds of different media available both commercially and ones you can easily make at home. Some are expensive, requiring special ingredients, while others are so cheap to make even in your kitchen that it’s practically free. I’ll keep you posted on the results.

10 thoughts on “Experiments

  1. Which media would be best for catching wild yeasts? I’ll be teaching a seminar to some high school students on yeasts and we’d like to capture some yeast for an experiment and possibly bake some bread with it.

    • Are you talking liquid or solid (plates)? In either case, you can boil some DME and either make DME plates or just wort. Leave open and see what you get. You can also do potato dextrose or sucrose (cheaper) plates. You’ll most likely get a ton of mold, but there will be some wild yeast floating around in the air. Try catching indoors and outdoors and see what you get (sound fun 🙂 )
      Also you can try MYPG agar plates (malt extract, yeast extract, peptone, glucose).

  2. Pingback: How to Build a Yeast Ranch « BKYeast

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  6. Just FYI, I have heard that Dan Carey at New Glarus flash pasteurizes most of the fruit beers that he makes so it might not be possible to cultivate anything from his beer.

  7. Pingback: Introduction to Hunting Wild Yeasts - Sui Generis Brewing

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