Re: Wyeast Bavarian: 48 hrs no show

John 'Shaggy' Kolesar wrote:

> I asked my wife, who has a biology degree. She says it's been a long time
> since she did anything with yeast, but here's the layman's explanation from
> what she can remember. The yeast cell's preferred environment is a warm one.
> Even lager yeast which will ferment cleanly at colder temps still prefers to
> live in a warm temp if it could have it's way. When you pitch a warm yeast
> into a cold wort, you are taking the cells from an environment they like
> and putting them into an environment they don't like, which is part of
> what causes the shock. The other direction, when you pitch a cold yeast into
> a warm wort, you are taking the cells from an environment they already do
> not like, and you are putting them into one that they prefer. Therefore,
> the shock isn't nearly as great.
>
> Also, with dry yeast the initial rehydration will take longer if you pitch
> from warm to cold, because during that shock stage the pores in the cell
> membrane that are letting the water enter the cell will not open up as
> far or as quickly.
>
> There's probably more to it, but that's as much as she could do since her
> college days were quite a few years ago.

Give my thanks to your wife! That's the most cogent explanation I've
heard yet, and it falls right in line with Tom's swimming pool analogy.

--------->Denny

--
Life begins at 60...1.060, that is.
.

Relevant Pages

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