Yeast prime temp time Q.

[kartracer2]

Question;
How long should/need fermention to be at the optimal temp. Let's say I'm using temp control (ice bath/swamp cooling/CoolStix what ever) but after x/hours it becomes a problem to maintain said temp. Is 50% projected attenuation enough to prevent any off flavor traits? (more-less?) Does it depend on yeast?
An idle mind has questions.
Thanks and Cheers,
Joel B.

 

[Golddiggie]

IMO, it really depends on the yeast and what temperature it's running at while you're actually controlling the temperature. Fermenting under pressure can mitigate the negative impact of fermenting too warm.

Personally, I let it go at my target temperature until it's completely done fermenting, plus some days. I set the batch I started on the 28th (fermented at 70F for WY1318) to chill to 50F so that the rest of the yeast will flocculate out. I'll harvest the yeast tomorrow late afternoon/evening, then let it get back to about 70F while it ages with oak (for another two weeks).

I typically allow my beers to go at least two weeks at ferment temperature, even when complete. It's easy with a glycol chiller (Spike CF10 with chill coil in place).

 

[TheMadKing]

Question;
How long should/need fermention to be at the optimal temp. Let's say I'm using temp control (ice bath/swamp cooling/CoolStix what ever) but after x/hours it becomes a problem to maintain said temp. Is 50% projected attenuation enough to prevent any off flavor traits? (more-less?) Does it depend on yeast?
An idle mind has questions.
Thanks and Cheers,
Joel B.

I would venture an estimate that 50% attenuation will allow you to ramp temps without ill effect, depending on the strain.

I routinely do this with lager fermentations and end up with clean lagers at the end.

 

[Bobby_M]

The primary reason temp control is more important in the first few days is that as the yeast get going, they throw a lot of heat into the wort and it starts running away on you. As it warms, it ferments harder, adding more heat, fermenting harder until you're a fusel alcohol and ester factory. If you keep the temps in check when activity is on the rise, you can let it warm on the back half and in fact, it's what I do on purpose. Generally 5 days in, I force a rise of about 5F on ales and 10F on lagers and leave it there until the beer clears.