Yeast culturing for root beer

I have been reading some of the great articles on this site and I have to say that even though I don't brew beer, the whole yeast culturing/rinsing/etc. stuff is kind of fascinating. However, this did raise some questions. I use Red Star Champagne yeast in my root beer. Assuming I can do it, is it worth me harvesting some of the yeast to be used in future batches? I only use about 1/4tsp of yeast for each 1 gal. carboy. What are the benefits of culturing your own yeast as apposed to just buying packets of it?

Crazy8 said:

I have been reading some of the great articles on this site and I have to say that even though I don't brew beer, the whole yeast culturing/rinsing/etc. stuff is kind of fascinating. However, this did raise some questions. I use Red Star Champagne yeast in my root beer. Assuming I can do it, is it worth me harvesting some of the yeast to be used in future batches? I only use about 1/4tsp of yeast for each 1 gal. carboy. What are the benefits of culturing your own yeast as apposed to just buying packets of it?

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None that I can think of, except to save money. Since champagne yeast is like .79 cents, and there are about 8 batches in one package, I can't see the cost savings for dry wine yeast.

I listened to a lecture series by a brewmaster loaded with international awards (you can sample about an hour of him on audible.com). Anyway a surprising thing I recall is he said to always use store bought yeast rather than reusing. Something about they become less potent, and have limits on reproducing only a certain number of generations. That reminds me how human cells are limited to a fixed number of dna splits except for cancer.

I know all about reusing, say sourdough yeast for 100+ years and such, although that refreshes it's supply from air exposure. And I reuse my cider-soda yeast by dumping it into applesauce. But I use fresh yeast for cider-soda, in spite of even bread yeast costing a fortune here. I have only found 1 (Japanese!) store that occasionally stocks generic bulk bread yeast at affordable costs.

Also that brewmaster said the type of yeast becomes almost irrelevant when your brew time is short. Champagne or beer yeast or whatever only makes a difference for long periods when they can imprint their flavor. I have used champ. yeast long ago at great cost(20x $0.75) and don't feel I miss anything with short periods of the bread stuff.

By experiment (or accident), I found cider-soda worked best for me by a super fast fermentation via a huge handful of cheap rotgut new bread yeast. Clean tasting with low alcohol. For you conventional bottlers that would cause a problem, but I don't bottle. Just stay in the original juice container and crunch the air out after some pouring. It reinflates in the fridge, but not to bursting point.

I had some second thoughts about the info I was passing along, and looked more into it. First of all, the absolute limit of dna splitting may be more of an animal thing... human cells can divide only about 52 times because we cannot duplicate a sort of tail end of our dna. Cancer cells can duplicate that, but our normal cells just countdown our 52 copies.

There is a fascinating tutorial on "the wonderful world of yeast" at http://invsee.asu.edu/srinivas/yeastmod/celldivision.html ... well, I aimed that at the cell division page, but you can start back on the introduction page by clicking upper left. They do mention that SF sourdough yeast is sort of a myth... it is 99% a certain type of bacteria with only a trace of wild yeast. Maybe that would make a good drink though!

Apparently the exponential phase of yeast growth is a budding process , which gives smaller cells than from true sexual reproduction where two come together to make 4. Some yeast divide evenly, but I get lost in tracking down why store bought yeast may be superior to recycling. Anyway there is interesting info there on the later stages of lifecycle, like how yeast can start digesting themselves and giving bad odors.