Finding a good home for all that extra yeast
I've been working with a local "craft bakery" to use my surplus yeast in their breads. So far, the test results have been rather mixed - some good, some not so good.
The idea is not especially new as this practice dates back for centuries - or so I am told. I'm hoping someone here has tried this out, or is doing it regularly, and can answer some basic questions:
1. When is the best time to harvest yeast from the fermenter (unitank in my case)? Same as it would be for repitching, I'd guess? What's the window?
2. How long can it sit before it can no longer be used? Again, I'd expect that the same rules apply to bread as it would to beer, but there are differences (limited food supply in dough compared to wort, maybe less oxygen?)
3. Storage conditions for the yeast - I'm thinking that a lower standard (temperature, container type) than used for brewing is acceptable, since mutations and even wild yeast contamination may be tolerable, since the yeast is not repitched, and is executed with each bake.
Any help - either speculative or experienced based is appreciated!
Last edited by Sir Brewsalot; 02-09-2005 at 08:26 AM.
I haven't worked anywhere selling to a brewery, but thinking of the process in bread, it is pretty similar to fermentation at start up, so, for what it is worth, I would work on the following assumptions
- crop as if repitching, store at no more than 4 deg C, aerate the yeast slurry vigorously say an hour before making up into dough - the yeast will not be able to digest the sugars and produce the CO2 if it is near dead.
Make sure they also get the middle crop you would use for re-pitching - first and last offs tend to be be less active, just as with fermentations.