- Inactivation of yeast
Handbook of Brewing, W.A. Hardwick, 1994
page 525 -
- So, am I to understand that a person in the latter hours of
fermentation could put an end to stubborn active yeast by heating wash
to 60C? At this temp no ethanol would be cooked off? Allow wash to
settle and still it. Would this not be a way to help settle your wash?
- --- In Distillers@yahoogroups.com, "headsmashedin" <headsmashedin@...>
> So, am I to understand that a person in the latter hours of
> fermentation could put an end to stubborn active yeast by heating
> to 60C? At this temp no ethanol would be cooked off? Allow wash toYes. I have written about this some years back. BUT, be aware that if
> settle and still it. Would this not be a way to help settle your wash?
> Heads McGoatlick
you go over 60C then you run the risk of the yeast spilling its guts
and stinking up your wash.
Assuming you use your still as a boiler, the correct way to do it is to
heat the wash (with suspended yeast) to 60C, then let it cool & settle
overnight, boiler still closed up to prevent things getting in or out.
Next day is stillin' day. Rack off the cleared wash back into your
fermenter, clean out the yeast sludge from the boiler & save it as
nutrients for your next fermentation. Now take your cleared wash,
refill the boiler and distil it off as usual.
After strip distilling, you can set your new wort while your spirit run
and boiler is coming up to temp. Or if you just do one single run of
the wash(some do), you set your new wort when the still boiler is free
and you have the spent beer (lees) to cook up the yeast. The strippate
will be fine until you want to do a spirit run. You can even store
strippate for extended periods as it is high enough abv to ward off any
infections. So here's the procedure...
Wort Set Procedure:
Use 1/3 of the total hot spent wash from the strip run. Fire the
boiler, add the previously saved spent yeast and bring it up to simmer
temp. This will purposely burst the yeast and spill the nutrients.
Add this mix back to your fermenter and dissolve your sugar. Then add
cool/cold water to bring it to the right temp and volume. Check the
pH and adjust it to 5 - 5.5 as necessary. Take and record an SG
reading. Add any other ingredients you want, stir it all up, pitch
your rehydrated yeast and stir it up again. Finish off by fitting your
air pump or airlock as per your normal procedure.
This is a very efficient way to recycle your spent yeast, your lees and
streamline your stillin' day. Of course if you don't want to start
another wort this soon, you will have to save the lees in a suitable
container and reheat them when you need to.