Fermentation temperature control protocol

I'm planning on getting a 7 cubic foot chest freezer off of craigslist to serve as a fermentation chamber. now that I'll have greater control over temps, what do you do as far as setting your temp control? Do you set it in the higher range of the yeast's optimal temp for the first day to get it going, or keep it the same temp the whole time?

Any other tips for someone that has accurate temp control for the first time?

I have a fermentation chamber that I built from plywood, 2x4's, insulation foam and a minifridge. I use a Johnson a419 controller for the temperature control. For simplicity I don't vary the temperature. I ferment in the lower half of the yeasts range. I find this gives me consistent good flavors. I feel that more off flavors are produced at higher temperatures than at lower temperatures,

mgr_stl said:

I'm planning on getting a 7 cubic foot chest freezer off of craigslist to serve as a fermentation chamber. now that I'll have greater control over temps, what do you do as far as setting your temp control? Do you set it in the higher range of the yeast's optimal temp for the first day to get it going, or keep it the same temp the whole time?

Any other tips for someone that has accurate temp control for the first time?

Click to expand...

No.


I'd set it near the bottom of the yeast's preferred range and keep it there until the ferment slows, then take it out and let it warm to room temp while I put another batch in to start fermenting. Once the bulk of the sugars are gone the yeast is more into cleaning up off flavors than into creating them.

Depends on what you want out of your yeast. If you want some of the esters then I'd set it a little higher (68*F for ale yeasts is what I use). If you don't want any esters then use the lower end of the temp range for the yeast (62*F for ale yeasts). For something like a Saison/Farmhouse Ale I let it go crazy at 80*F+.

Also whatever temp I'm using, I let it go 3-4 days then ramp it up about 5 degrees to help it finish. At that point the yeast should be done with the phases that cause off flavors and a little temp bump will help them finish the job.

Do you guys throw the fermentation vessel in the temp controlled chamber pretty much right after pitching the yeast, or do you let it sit at room temp (which for me is typically a bit higher than ideal fermentation temps) for a bit?

I like getting down a few degrees below pitching temp, pitching, then letting it rise up to my desired temp. Most of the time I my ground water is cold enough to get it there, but otherwise it is straight into the chamber for my beers.

mgr_stl said:

Do you guys throw the fermentation vessel in the temp controlled chamber pretty much right after pitching the yeast, or do you let it sit at room temp (which for me is typically a bit higher than ideal fermentation temps) for a bit?

Click to expand...

Kudos to you for asking about the important stuff and for getting set up to control temps. Get ready to take your brews to the next level. You're gonna enjoy the results.

Assuming that you pitch sufficient yeast in the first place (one of the other keys to brewing good beer), here's the profile that will serve you well for most styles (excluding Saisons, certain other Belgians and the few beers where a strong ester character is desired):

1) Chill the wort to a few degrees below the low end of the optimal range for the yeast being used. If your chiller won't get it that low, put it in the chamber a few hours (or several if needed) to get it down there.

2) Pitch yeast and set the controller to the low end of the optimal range. Tape the sensor to the side of the fermenter and insulate over it with some bubble wrap or something.

3) After krausen falls (airlock activity slows significantly), start letting the temp come up on its own over a period of a few days until you're around the upper end of the optimal range.

4) Once fermentation is complete, reset the controller to 35*F and leave it at that temp for 5-7 days (a cold crash) to clear the beer and firm up the yeast cake.

A few note about certain commonly-used strains - US-05 is best started at 64-65*F. Cooler than that can produce some peachy notes that some folks don't like. Nottingham will ferment as low as 55*F, but it doesn't like above 67 when active (it gets some funky esters warmer than that). WLP002/1968ESB can drop out early if allowed to stay cool after activity slows, so it should be brought into the upper 60's after the first few days at 63-64*F.

http://www.brewersfriend.com/yeast-pitch-rate-and-starter-calculator/ is a good pitch rate calc, although it does use a too conservative 100 million cells per gram of dry yeast. Microscopic counts reveal that it's about twice that, so an 11g packet rehydrated to fine for an ale up to 1.060.

Thanks for the knowledge Big Floyd! That's exactly the type of info I was looking for. Unfortunately the lead I had on craigslist fell through, so I'm back on the prowl for a deal on a 7 cubic foot chest freezer.

I like to know the temperature of the wort/beer and not the air or some other liquid in the fermentation temperature. I tape the temperature controller probe to the side of the fermenter. After taking multiple temperature readings with a trusted thermometer over several batches I learned that my wort/beer is usually 4F degrees warmer than what the controller probe is reading. I suggest doing the same for your system once you get it going. Some yeast will produce an entirely different beer at 72F than they would at 68F.