What's worse?

[Chrispy92]

So having a random late night thought, need some help.

I've got a batch fermenting at the moment, a biggish IPA using S05. It's in a water bath and I've been adding frozen bottles to it periodically. However; I haven't had the time to be super consistent with it, so the temp has been fluctuating up and down between 20C and 24C over 12ish hour periods. My basement sits at around 24-25 and is pretty consistent.

So my question is what's worse for creating potential funky esters with S05, having a stable consistent temp that is a bit high (ie 24 ambient basement with no ice bath) OR... Creating inconsistent but periodically lower temps (using ice bath) and creating drops and rises in temp??

Help

 

[ncbrewer]

I'm not an expert, but from the book "Yeast", running heating ducts near the fermenter by day and off an night can ruin the fermentation - yeast don't handle large fluctuations well. But since 24C is too high, I'd go with no ice, but a wet towel over the fermenter to keep it a little cooler. Some brewers run a fan, but I'd want to be sure it's rated for continuous duty.

 

[Peam]

I think I would be more alarmed by the high temperature. The ice bath will certainly help bring that down. As mentioned by @ncbrewer I would keep a wet towel or something over it to help keep it cool. That should also help with the temperature fluctuations

 

[ncbrewer]

Another thought - the Cool Brewing insulated bag might be a good option. I haven't tried it but have read many positive reviews. As I remember, It doesn't need replacement ice near as often as a standard swamp cooler with a tub.

 

[Chrispy92]

Mmmm thanks for the input. I kind of thought the fluctuations might be bad. Having a bit of a stupid heat wave here which is making it hotter than usual, I'll drape a Tee over the fermenter. It's on day 4 of fermentation now and still had full krausen. I'll try keep the temp down a bit and minimise fluctuations as best I can then once it's finishing up I'll let it ride out at 24....

 

[Peam]

With temperatures like that you might be better suited with farmhouse yeasts until you're able to get that temperature under control. Who doesn't love a good Belgian style beer anyway right?

 

[hottpeper13]

Mmmm thanks for the input. I kind of thought the fluctuations might be bad. Having a bit of a stupid heat wave here which is making it hotter than usual, I'll drape a Tee over the fermenter. It's on day 4 of fermentation now and still had full krausen. I'll try keep the temp down a bit and minimise fluctuations as best I can then once it's finishing up I'll let it ride out at 24....

By day 4 you already made all those off flavors so now you need the yeast to clean up as much as possible. Maintaining steady temp at the top of its range is what you need to do now. If you chill after that high of a fermentation the yeast will stress out. And also time is your friend,sometimes those flavors mellow out with a long conditioning phase.

 

[sky4meplease]

Another thought - the Cool Brewing insulated bag might be a good option. I haven't tried it but have read many positive reviews. As I remember, It doesn't need replacement ice near as often as a standard swamp cooler with a tub.

+1 on the CoolBrew bag. I have a couple and they work great. It does take some time to learn them. It's is easy to cool too fast or too far if your not paying attention.
I too would be more concerned with leaving the ideal range for the yeast but I don't sweat too much a swing in temperature as long as it doesn't happen too quickly or stray outside of what is optimal.

 

[ncbrewer]

With temperatures like that you might be better suited with farmhouse yeasts until you're able to get that temperature under control. Who doesn't love a good Belgian style beer anyway right?

Speaking of yeast strains, Mangrove Jack's Workhorse yeast is supposed to work well at higher temperatures. I haven't tried it, but it might be just what you need for non-Belgian ales.