Newbie Yeast questions!

[ajchafe]

Hi everyone,

New to the forms, long time lurker though.

After extensive reading of the "Think you ruined your beer? Set your fears aside!" thread and some searches, I can't find the answer to my question.

Basically, my beer was fermenting VERY slow after 18-24 hours, and my kitchen was very cold, so I put some blankets around it and added a heating coil to warm it a bit. Ended up warming it too much I think (30C).

The yeast was going much better, we took off the coil and blankets to let it cool, and about 6-8 hours later it has totally stopped.

Is my yeast dead? Can I reactivate it? Can I add more yeast?

 

[John8251]

How cold was it in the kitchen?? I say leave it alone for another 5 days or so and then take a gravity reading and see what you got.

 

[ajchafe]

Thanks for the reply!

I don't have an exact temperature (maybe I should invest in a good thermometer). But it's cold enough that the stick on thermometer I have for my primary fermenter dips below it's minimum range of 15C unless wrapped up. The recommended temperature on the yeast package was 15-20C.

I will wait and see what happens. But let's assume the worst and the gravity has not changed, can I safely assume that the batch it ruined?

It's all grain btw (my first try!).

 

[boydster]

I doubt you killed the yeast, but at that temp they could have finished the fermentation very quickly. I agree, wait this one out and see. Give it 2-3 weeks of sitting in primary before you touch it and when you take a hydro sample, taste it to see what you have.

 

[ajchafe]

Ok sounds cool, I will keep an eye on it for now. If nothing has happens in that time, is it possible to just add more yeast?

 

[unionrdr]

Large temp fluctuations can shock the yeast into settling out. Try to stabilize the temp at around 66-69F & give it a gentle swirl to stir up some yeast. It should get going again by the next day if it appears to have stalled.

 

[BigFloyd]

It sounds like you've been taking that yeast on a temperature roller coaster ride. They don't enjoy that.

By starting cool, the activity was happening, but not with the vigor you wanted to see. By bringing the temp up to 30C (way to hot), you got it going alright, but probably caused off-flavors from stressing the yeast. When it dropped back down to 15C or lower, whatever remaining activity you might have had ceased and the yeast dropped out. They're not dead, just sleeping. What's your gravity now?

Adding more yeast won't fix anything. It will simply make your beer more yeasty. You're going to need to figure out a technique to maintain a nice, constant ferment temp. A large tub of water and aquarium heater may be a good solution for you.

 

[ajchafe]

Thanks for the advice. In the past with kits we have never had a problem keep the temp in the right range, even last winter in the same room when said room was even colder!

I will try warming it and giving it a gentle stir if the OG has not changed from the first test.

 

[BigFloyd]

Thanks for the advice. In the past with kits we have never had a problem keep the temp in the right range, even last winter in the same room when said room was even colder!

I will try warming it and giving it a gentle stir if the OG has not changed from the first test.

I wouldn't doubt that the gravity is now lower than the OG. The issue is having the yeast drop out prematurely due to the temp fluctuations, leaving the fermentation unfinished.

Unless you've hit the target FG in a couple weeks, I'd first warm it up to 68-70*F and then very gently stir that yeast cake up.