In listening to a Beersmith Podcast from 2018 (#168), John Palmer talks about warming the beer in your Fermentor up 5-8 degrees Fahrenheit after the growth phases (Diacetyl rest?), so the yeast is still thinking about consuming and not shutting down. More so for lagers, but still applicable to ales (like I’m brewing). That way it can take care of the byproducts that sometimes lead to undesirable flavors. If I don’t have a Tilt in the fermentor, how should I gauge WHEN to use my Inkbird to increase the temp? He says ‘towards the end’ How many days before I rack the beer? Should I just use the bubbler as a guide? The bubbler usually stops after 2 sometimes 3 days for me. Should I not bump up the temp 5-8 degrees F because my fermenting temp is in the 60’s for my ales?
Palmer’s How to Brew, 4th Edition states “Therefore, as you see the bubbling in the airlock start to slow down toward the end of the high growth phase, approximately day 3 for ales and day 4 for lagers, raise the fermentation temperature by 9F.” I raise the temperature after three days - seems to work well.
Great - Thanks. He mentioned days in the podcast, but I was wondering if there was a set rule or more specific timeframe.
I share your concern. Certainly, fermentation won’t proceed at the same rate for all beer batches. Ideally you would check the SG to know when to raise the temperature. White and Zainasheff’s book Yeast suggests raising the temperature when 1/3 - 1/4 of the fermentation remains, then raise by 4 - 10 F over 1 - 2 days, but doesn’t give a time frame. I just keep things simple and go with 3 days. I’ll stay with that as long as I’m happy with the results. From checking the airlock bubbles, I’m probably a little late on some batches, but it seems to be close enough (so far).
Esters are generally created in the first 4-5 days of fermentation. After that you can safely raise temp. My usual schedule is 5 days at 65F, then bump it up to 72.
In HtB pg 94 Table 6.2, Palmer says 2-5 points from FG: for Lagers at day 4 of 6 raise temp 14-18°F and leave for a minimum of 6 days (up to 12), for Ales at ~day 3 of 4 raise temp by 5-10°F for a minimum of 4 days (up to 8).
The Tilt does make this visually easier but familiarity with the yeast strain can help, too.
Thanks, Denny! Do you keep it at 72 until you are ready to keg?
Nope. After a totally arbitrary 3-5 days at 72, I drop it to 35 forv5-7 days before begging. After conversation with Palmer, I’ve tried dropping it slowly as well as just crashing it. Can’t tell a difference between the 2 methods.
Shoot - sorry. I was referring to ales and how Palmer mentioned this raise in temp after 2 growth phases is applicable to them as well. I guess normally I would leave it around the yeast preferred temp range for that second week, but i’m unsure.
Yeah, that’s what I was talking about. I do the same for ales and lagers, but I usually give lagers longer at a lower temp before I raise it.
Okay - thanks! I have a lot to learn about fermentation. I was just leaving it as close to the yeast preferred temp range and trying to stay as close as possible to that for the whole 2 weeks. Maybe that’s why my brews have tasted minerally. I do NOT have a fermentation chamber.
There are easy ways to control fermentation temp. I use to put the fermenter in a large plastic bucket of water. I could add ice packs or an aquarium heater to the water to control temp. The yeast temp manufacturers recommend is just an approximate suggestion. I often start yeast a lot cooler than the “recommended” range.
My yeast (Wyeast 1272 American I| Ale Yeast) says 65-72 F and I’ve had it 69 - 70 up to 72 most of the first three days. Bubbling has stopped - should I bump it up to 79 F ?
You are safe to leave it as is. No reason to take it up to 79°… That will just potentially stale the beer quicker. If gravity is stable, you are ready to package!
The diacytel rest reduces time to finished beer andis good insurance for lagers. If you have a good healthy fermentation and have enough time the D rest is not required.
I haven’t had healthy fermentations in my opinion. The airlock bubbles like crazy for 24 hours and on this most recent batch, stops after 3 days. I’d like to clean up any of the off flavors that I have noticed in my first few batches. I’ve never done a diacytel rest, so I thought I would give it a shot. I bumped it up 7-8 degrees last night and this morning it was bubbling again. I’m going to transfer to a secondary this Sunday. The upper 70s temperature does make me hesitate for sure, but I usually start my fermentation at just below 70 or just above because I don’t have a place in the house that is consistently in the 60’s. It is either room temp 69-70, or 50’s in uninsulated part of my basement.
If you’ve had off flavors, a diacetyl rest is one place to start (if you have had diacetyl flavors). Any thoughts on what the off flavors are? If you know any other homebrewers locally, they could maybe help out with diagnosing. (forum diagnoses will be of highly variable utility, because none of us have tasted it and most will give you strong opinions ranging the gamut from helpful to useless!).
Airlock activity is only a rough proxy for fermentation activity – you can have the final push to full attenuation without much CO2 evidence, or very irregular evidence. It’s possible you had a stalled fermentation…but resumed airlock activity could just reflect you moving the fermenter (it jostles the CO2 out of solution). Diacetyl seems unlikely at those temperatures, unless you are bottling/kegging super super early.
My usual “rule of thumb” for ales in the 60s to lower 70s is package at 10 days (although it’s usually 14 to 30 days, just given my family and work schedules). For most (nearly all?) regular ale strains, that’s more than enough for it to finish out and clean up diacetyl, acetaldehyde, etc. You can almost always skip the secondary fermenter – truly! For most styles, it just adds work and adds opportunity for oxidation and contamination.
Doesn’t sound like there’s anything wrong with your fermentation. At the fermentation temps you use, and rest is really unnecessary. Are you aware of why you increase temp for a d rest?
I was watching the Beersmith Podcast (168) and Palmer was talking about the maturation phase where a lot of crappy byproducts are present. If my yeast shuts down early because it thinks there’s nothing else to eat, they don’t get to eat the byproducts that are still present. Bumping up the temp keeps them active? At least that’s the general idea that I have. I’m new to the game, hence all the questions. I can only read books and post here - I don’t have anyone to reach out to otherwise.
P.S. I bought your book, and I mainly read that and HTB. I really appreciate all the advice here
Another option is to agitate the fermenter a bit, to get yeast back into work (and that’s also one positive product of transfer to secondary).
I know you’ll get it figured out – trial and error and learning can be frustrating, but you will see improvements with each batch as you figure out what works for you.