Technique

Yeast Bank: Demonstrates how I make and maintain my yeast bank in the lab.

Homemade Candi Sugar: While not authentic Belgian Candi sugar, inverting sugar can provide a unique flavor to your brew.

Oxygen: My first beer using pure oxygen.

Hop Bitterness: Molecular origins of bitterness derived from hops.

Partigyle: Different methods of partigyle for multiple wort production.

Decoction: Although not entirely correct, this was my first basic attempt at a decoction mash. I need to repeat this again.

Homebrew in under 12 days: My experience in brewing a batch of beer, from grain to glass, in twelve days.

Extract Brewing Tips: Not just tips for extract brewers, but applies to all-grain brewers as well.

4 responses to “Technique

  1. Bob Teichmann

    Jason, I hope you don’t mind if I ask a couple of questions. We were discussing yeast harvesting in the last NJ Hopz-East meeting. Consensus was that it could only be performed 4-5 x before the yeast becomes unviable. Why is this and how to prevent this? I’ve become quite attached to my strain of WPL-001! Its like my pet.

    • Hi Bob!

      Well, the word “unviable” is pretty black and white. The cells will not simply crap out and die but rather accumulate mutations over time until the ideal fermentation profile is lost. Honestly, I never tried re-using yeast as I find it more convenient to buy some WLP001 and make a starter.

      However, there is a solution to your problem! Basically with old age yeast, they need to be completely revitalized. Which means having the grow biomass from a excess source of wort. In other words, you will need to store at a particular “passage” if you want to reuse it. 4-5 is not a solid number, and if you like the way your WLP001 performs, I would through rinse the yeast cake and keep a small amount in the fridge. Every month or so, inoculate a small amount of yeast (we are talking a teaspoon or less of slurry) in a one liter starter. Even better would be to freeze the yeast in some glycerin.

  2. Bob Teichmann

    Hi Jason,
    Thanks for the reply. Sorry for my delay. Sometimes letting the info rattle around in my head for a while helps… Is your idea that by inoculating a small amount of yeast periodically, you are encouraging many “daughters” to grow (beautifully said in a blog from one of your yeast classes!) ? This growth would keep the yeast young and vigorous. Presumably harmful mutations would not be so successful reproduced.
    Bob

    • Hi Bob,

      That us exactly what I’m saying! Basically you are shifting the population of cells to younger daughters. However, I’m not sure if this has any effect on mutation rates. Keep in mind that it is quite hard to generate mutations quickly. One would have to stress the yeast over multiple generations to see an effect.

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