Fermentation temp. What's too high?

[ashopis]

Hey there,

I make mostly NEIPAs and I haven't used temp control. I just ferment at room temp. In the summer that means low to mid 70s. Is that too high? What problems will arise at this temp? What off-flavors?

I use Wyeast London III yeast.

Thank you!

 

[Jtvann]

Temp inside the fermenter can be quite a bit higher than ambient room temp. If its 70 degrees room temp, that could be 80 degrees inside the beer. That could lead to unwanted, or possibly wanted esters or fusel alcohol.

Temp control is one of the earliest things to get to improve the quality of your beer.

 

[histo320]

A cheap and easy way to help bring the temp down would be to use a swamp cooler.

Just fill up a storage bin with water and place the fermenter inside. Add frozen gallons of water or frozen 2 liter bottles of needed.

My basement is around 65F and withbuse of the swamp cooler I fermented my last batch at 62.

As for off flavors, fermentations at high temps can cause eatery off flavors and I think you risk diacetyl which tastes like buttered popcorn.

I wouldn't worry too much, it will probably still be a solid beer.

 

[mongoose33]

The best thing you can do is control temp at the recommended level from either the yeast package itself or the recipe.

For most ales, that's in the 60s. As @Jtvann notes above, fermenting at 70 could get you temps as high as 80, which will not be what you want.

There are lots of ways to keep ferm temps down. @histo320 notes the swamp cooler, which is the cheapest way to do it. Some may put frozen water bottles in the water of the swamp cooler to help it, if the ambient is fairly high. Below is a pic of a swamp cooler.

The preferred (and more expensive) way is to use a freezer or refrigerator to control temp, using a controller to monitor temp and kicking on the unit when it needs to keep temps down. I've included a few pics below showing my two ferm chambers, one a larger refrigerator I bought for a song, the other a tall dorm-style refrigerator for which I paid $60. Both are controlled by Inkbird 308s, which are excellent yet inexpensive controllers (I have five of them).

You can even go uber-pricey by buying a glycol chiller and using a tubing system to control temps. For most home brewers, though, the refrigerator/freezer approach is more than enough.

 

[VirginiaHops1]

Swamp cooler will work fine but check yard sales or craigslist or whatever online marketplace you prefer and keep your eyes open for a chest freezer. People sell decent ones for dirt cheap they don't need anymore. I got one for $25. Add an inkbird temp controller and you're good to go. Advantage of that over swamp cooler is you can also use it to go to lower temps to ferment a lager or cold crash.

 

[ashopis]

You all are seriously talking me into a fermentation fridge. Been looking around on craigslist for a mini-fridge. Is it a problem if it has a freezer section at the top?

Also, regarding cold crashing. How do you avoid sucking oxygen back into the fermenter?

Thanks again.

 

[mongoose33]

You all are seriously talking me into a fermentation fridge. Been looking around on craigslist for a mini-fridge. Is it a problem if it has a freezer section at the top?

Also, regarding cold crashing. How do you avoid sucking oxygen back into the fermenter?

Thanks again.

Some people bend the freezer section down out of the way, but you're taking a risk to kink or crack the lines.

I did this instead:

I took a bottle filler (plastic tube), cut off about 2", and inserted into a stopper. Added some tubing, and voila! Room to spare.

You can terminate that in a jar of Star-San, or even set it up to use an S-airlock. There are also ways to use jars to avoid suckback.

 

[El Nino]

If you can afford it, get a fridge / freezer. Out of anything you can invest in to give your beer improved quality, temp control is it.

 

[snarf7]

I agree with @mongoose33 that a dedicated fridge with the inkbird is the way to go, absolutely a must for lagering and cold conditioning for me. That said, I'm quite fortunate to live in an old farmhouse with a cold cellar that never gets above 60F even if its 100F degrees outside. I can actually use different steps on the way down to the cellar to pick the perfect spot for it _...top step is 64.5F, halfway down is 61F, cellar floor is 58F. I got 2 of the Idylis 7.1-cu ft chest freezer for a song and used one as a keezer and the other as my fermentation chamber, works great and they can fit 4 kegs

I also find that fermenting on the cooler side of the temp range for the yeast yields the best results...it takes a bit longer but it turns out better. What I'll often do is for a typical S-05 brew is let it start at 68-72F for a couple days to get it cranking then drop it down to my target temp (around 66F) for the remainder of the time

 

[ashopis]

Does anyone have a good link to a cold crash suck back solution?

 

[histo320]

Does anyone have a good link to a cold crash suck back solution?

Here's a link to another discussion on suck back.

https://www.homebrewtalk.com/forum/threads/cold-crashing-mylar-balloon.668309/

Cold Crashing / Mylar Balloon

 

[bleme]

You all are seriously talking me into a fermentation fridge. Been looking around on craigslist for a mini-fridge. Is it a problem if it has a freezer section at the top?

Also, regarding cold crashing. How do you avoid sucking oxygen back into the fermenter?

Thanks again.

Take a fermentor (empty) with you when you go to check out the fridge, just to make sure it fits in there.

Also, regarding swamp coolers, if you live in a dry climate then draping a black t-shirt over your fermentor and setting a fan to blow on it can drop the temp by 10F.

 

[Ninoid]

Simple for summer use yeast for higher temperatures, overpitch and transfer packaged beer to fridge one more week after carbonation.
M29 can ferment very good beer on 33'C (91'F), US-05 work up to 28'C.
I make very good beer with overpitched BE-134 on 35'C.

 

[bleme]

You could also use one of the kveik yeasts. They are good up past 100F and can produce fruity esters, complimentary to a NEIPA.

 

[Jag75]

You all are seriously talking me into a fermentation fridge. Been looking around on craigslist for a mini-fridge. Is it a problem if it has a freezer on top

Fermentation temp is just about as important as cleaning and sanitation. Anyone who intends to make beer should be ontop of temp. You will be happy with the fridge and inkbird 308.