How critical is temp control AFTER active fermentation is over?

[TANSTAAFB]

I have been brewing for a little over a year now and AG for over half of that. I feel like I am pretty well informed as I study brewing constantly in an attempt to make better beer. I have read everything I can get my hands on regarding this issue including "Yeast" by White and Zainasheff, articles, threads, brewing books, etc., and I have not found a direct answer to my question. They all seem to assume that if temperature control is used, it is used for the entire time the brew is in a fermenter. I also found one thread in the beginner's forum that asked the same question but got less than satisfactory answers.

From what I have read it seems that the first week is the most critical for temperature control while fermentation is active. I have time to brew way more than once a month but I have a Johnson controlled beverage cooler that will only hold one fermenter at a time. I typically primary for 3-4 weeks. I understand that a few degree rise is normal for a diacetyl rest, but I brew in Texas, so we are talking about a bigger swing once removed from the temp controlled chamber. Temps could easily hit the low 80's.

So, are there any scientifically supported reasons NOT to allow the temperature of my beer to rise from the 68*F I typically ferment ales at to the lower to mid 80's for 2-3 weeks AFTER active fermentation has ended? Am I risking off flavors from some activity of the yeast at higher temp? Will they release compounds at higher temps they would otherwise retain? Everything that I can find seems to support the idea that the yeast clean up FASTER at higher temps.

Thanks in advance for your help

 

[Jcmccoy]

Okay I am no expert but from what I have read an heard... for ales temps should stay around fermentation temp +- 5 degrees. So most of the time we are fermenting at 68~ so from 63-72 is fine. But the higher the temp the faster oxidation will happen. So on the cool side is better once fermentation and conditioning is done.

 

[joel4482]

No scientifically supported reason, just common sense. If the beer is done fermenting then put it in bottles or a keg. Condition/carabonate it then keep it cold. The warmer the beer is stored the better chance of oxidation, infection, and loss of hop aromas. You only need 2-3 days of Diacetyl rest up to 72 degrees to "finish" up fermentation. Any higher temp will not render it undrinkable just less drinkable from oxidation and loss of aroma.

 

[Olddog]

How about on the cold side? I have a batch going using WLP001 California Ale yeast that was in my garage fermenting at 54 degress (according to my fermometer on the side of my better bottle). It's had a nice krausen on it for the last four days so I'm not super worried about it but will the flavor be affected at all?

 

[TANSTAAFB]

No scientifically supported reason, just common sense. If the beer is done fermenting then put it in bottles or a keg. Condition/carabonate it then keep it cold. The warmer the beer is stored the better chance of oxidation, infection, and loss of hop aromas. You only need 2-3 days of Diacetyl rest up to 72 degrees to "finish" up fermentation. Any higher temp will not render it undrinkable just less drinkable from oxidation and loss of aroma.

You're in my old home town joel!!! I grew up in Newport when it was still small, funky, and slightly less commercial...have a pint for me ya lucky bum

There are VERY good reasons not to rush the beer off the yeast. This issue has been beaten to death on these forums and many land squarely in one camp or the other with no intention of budging...I don't want to argue the merits of extended primaries, racking to secondaries, etc. I will continue to keep all but my most simple session beers on the cake for at least 3 weeks. I have seen considerable improvement since gaining patience.

What I want to know is whether warm bulk conditioning for a week or three is detrimental to my beer and the reasons why. I am not concerned about oxidation in that short a span with a nice protective layer of CO2 firmly in place. I will control temps during the first week to two weeks then rotate that fermenter out to control the beginning of another batch and so on. I just don't have a cool spot in the house and I tried the swamp cooler thing last go round and it was a PITA! It slowed swings but did not prevent them.

 

[erikpete18]

I do about the same thing. I've got a mini-fridge ferm chamber that can hold one carboy, so I generally keep it there for 2 weeks, then move it out to room temp for another couple weeks until I think its done (at least on normal-sized brews). Granted, my room temp is quite a bit lower than yours (~70).

If I remember correctly, most of the ester production happens during the log phase of yeast growth (first day or so). Once the yeast are done growing and fermenting, there shouldn't be too much off-flavor production. No scientific facts, but it would make sense that raising the temp after fermentation could speed up the "cleaning up" process a little, but even that I'd wager is more time dependent than temp. So long as the temps don't get really high (90s) or the beer sits there for a long period of time I wouldn't worry about it too much!

 

[TANSTAAFB]

I appreciate the responses. Guess I was looking for someone to post an "I live in Death Valley and I've done that for years and my beer is awesome/ terrible, never do that or you will have sh!t beer no one will want to drink" response or come up with some nugget of information as to why it is either a great or terrible idea...Looks like I will have to experiment and post back myself!

Most of the beers I'm planning to make in the near future are rebrews, so I'll have something to compare to. If I truly risk screwing up my beer I have an extra fridge I can hook the Johnson controller to, it would just be a pain to swap everything around.

 

[elproducto]

I do the same thing.. my chest freezer/ferm chamber will hold 2 plastic pails. If I need room, I take one out after I think its done primary ferm i.e. 5 days. Now this is for my house strain US-05, and I know it pretty well. I've never noticed any off flavors in the beers I've taken out early. My guess is, as erikpete said, once the majority of the work is done by the yeast, the chance of off flavors is minimal.

I probably wouldn't do it with a slower yeast, or something I really wanted fine temp control on like a Saison.

 

[TANSTAAFB]

I do the same thing.. my chest freezer/ferm chamber will hold 2 plastic pails. If I need room, I take one out after I think its done primary ferm i.e. 5 days. Now this is for my house strain US-05, and I know it pretty well. I've never noticed any off flavors in the beers I've taken out early. My guess is, as erikpete said, once the majority of the work is done by the yeast, the chance of off flavors is minimal.

I probably wouldn't do it with a slower yeast, or something I really wanted fine temp control on like a Saison.

I'm a little confused by this...fine control for a Saison? I was considering exploring Saisons because they are traditionally brewed hotter w/ less temp control. Even my regular Belgians I start low then let ramp up to the high 70's/ low 80's. I brew a lot of Belgian styles but have never done a Saison and I was actually contemplating starting a "What's your favorite Saison recipe" thread today! What temp control are you referring to?

 

[elproducto]

I'm a little confused by this...fine control for a Saison? I was considering exploring Saisons because they are traditionally brewed hotter w/ less temp control. Even my regular Belgians I start low then let ramp up to the high 70's/ low 80's. I brew a lot of Belgian styles but have never done a Saison and I was actually contemplating starting a "What's your favorite Saison recipe" thread today! What temp control are you referring to?

Do you keep your house at 80 degrees plus? According to Jamil Z, the ideal ferm profile for a Saison is starting at 68 and ramping up to 80 degrees +. That's a pretty wide spectrum for which I would think you would need temp control. I know here in Canada, there is no way I could properly do a Saison without temp control, especially in the winter. If you want the Wyeast 3724 to finish out, you'll def. need to control the temp.

 

[TANSTAAFB]

Do you keep your house at 80 degrees plus? According to Jamil Z, the ideal ferm profile for a Saison is starting at 68 and ramping up to 80 degrees +. That's a pretty wide spectrum for which I would think you would need temp control. I know here in Canada, there is no way I could properly do a Saison without temp control, especially in the winter. If you want the Wyeast 3724 to finish out, you'll def. need to control the temp.

Gotcha. That is the same temp profile I use for all my Belgians. I thought Saisons were warmer starts because of the historically warm farmhouse brewing. I will have to read some more!

 

[elproducto]

I guess my rule of thumb, and I'm by no means an expert is... I try to control the temps for the specialty yeasts. I know my US-05 is a workhorse, and is pretty tolerant of temp swings, but when I'm bring that Kolsch, or Belgian where I want specific yeast profile.. I try to control it for the majority of fermentation.

Good Luck!

 

[jfowler1]

"How critical is temp control AFTER active fermentation is over?"

What a great question. I saw this thread when it first started, and really wanted to jump in, but I was not sure how to approach the question.

So I settled on this.

- Not as critical as temp control DURING fermentation.

I find myself in a similar situation as the OP. I ferment in a mini-fridge, and I use a Johnson Controller, ferm wrap, and carboy cap thermowell to dial in a temp. I have found it makes a huge difference in the quality and repeatability of my beers. The downside is that it limits me to fermenting 5 gallons at a time, and I really can't even think about my next brew until my last beer is out of the chamber and bottled. I prescribe to leaving the beer in the primary for 3 weeks, to allow ample time for fermentation and conditioning. Given that timeline, I can really only do 12 batches a year - if I keep on schedule.

So clearly, from an advice standpoint, I suggest controlling the temperature for the duration of conditioning over letting conditioning temperatures ride in favor of producing more beer. I value control over quantity (if quantity risks quality).

I'll offer two sources for my reasoning.

1st - Jamil.
I have listened to so much Jamil, I feel like I know the guy, but there is something kind of funny about all the interviews and shows he does; he never really commits to a solid timeline for how long he keeps his beer in the primary. He makes it very clear that he prefers to leave all beers in the primary for 2-2.5x the length of normal fermentation, but what exactly is a "normal fermentation"? He seems to kind of fall back on when it is done, it is done. However, this exact question came up (I think it was on an episode of Brewstrong) and IIRC, he basically gave my answer; not AS important as control DURING fermentation. Again, you are kind of left to decifer what that means.

2nd - BBR
I just listened to an old episode of Basic Brewing Radio. The host, James, conducted a tasting panel to test the effects of storing bottled beers at different temperatures. The concensus was basically that even when bottles were kept at various temps for just a few weeks, there were obvious differences in their flavors - be it oxidation, changes in hop aromas, etc. I take their findings to show that temperature - regardless of the step in the process - will effect the character of your beer. Granted, that effect may be on a sliding scale between the day you pitch and the day you drink, but the effect is still on the "scale".

So for that reason, I say 1 batch at a time. Again, quality over quantity.

Joe

 

[ibbones]

I can't answer the OP's question with a solid answer but...
I have a chest freezer that will only hold two buckets/carboys. I brew a batch and set it in, then a week/day later, brew the second batch. after about two weeks at a 66* range, I take the bucket out and set it in the closet ( in South Texas) and brew another batch. After the 3-4 week timeline, I keg and give it a shot to about 30# pressure and set the keg in the garage. After I brew five or six batches and have some kegs built up for a pipeline, I then use my chest freezer as a keggerator and crank the temp to around 36*. I can't brew until I drink what I have because it's the only place I can ferment.
So far, it is working. If only I could have two freezers, one to ferment and one to serve in.

 

[TheMan]

Do you keep your house at 80 degrees plus? According to Jamil Z, the ideal ferm profile for a Saison is starting at 68 and ramping up to 80 degrees +. That's a pretty wide spectrum for which I would think you would need temp control. I know here in Canada, there is no way I could properly do a Saison without temp control, especially in the winter. If you want the Wyeast 3724 to finish out, you'll def. need to control the temp.

I don't agree with this at all. I have used 3724 twice now and I just pitch it at room temp and let it go. My apartment hits low 80's in the day. I haven't had one issue getting it to finish, and my saisons were dry as a bone. I've heard of people having issues with this strain and never understood it based on my experience.

 

[beerkrump]

Be aware, as a general rule, that for every 10° C that the temperature rises the rate at which chemical reactions occur doubles.

 

[TANSTAAFB]

I spoke to an OG homebrewer today about this issue and I got much the same response as Jamil. "Do high temps affect flavor after active fermentation is over?" Short answer; Yes, but not as much as during active fermentation. He said the effects depends on strain, temp, and time. The yeast may release phenols, but not as much as in the beginning of fermentation and if released at higher temps but then lowered later the yeast will reabsorb them. This may not be a negative depending on the style and may not be an issue depending on the strain. Ester production occurs primarily in the beginning of fermentation so should not be as much of an issue.

He even went so far as to say that he keeps his fermenters in an air conditioned room at around 70-72*F, lets them go with no more temp control, kegs or bottles, then waits and lets the yeast clean up after themselves. He only temp controls if he secondaries or lagers, but he builds huge pipelines, works in a giant beer store, and has a lot of patience! He is never in a hurry to drink his latest brew because over 30+ years of brewing he has nailed down his recipes and process and pretty much knows what to expect from each recipe at each stage of fermentation, conditioning, and aging.

Once again, there is no magic bullet, there is no right answer, and I am forced to meditate on the zen of homebrewing before deciding what I should do in my particular circumstances, with my gear, my process, and my recipe...repeat for the next brew. I love this hobby

 

[TANSTAAFB]

I decided to conduct a split batch experiment to test this out for myself. I have a 10 gal batch of Saccharomyces' Belgian Pale Ale boiling now which I plan to split w/ 5.5 gal in a bucket and 4.5 gal in a BB carboy. I will ferment both until Friday 4-15 in a temp controlled fridge (decided to move my Johnson controller to the big fridge until I slow down a little!) and then I will pull the carboy out and let it finish at room temp between 75-80*F while the bucket remains at 68*F for the remainder of fermentation (3 weeks total). I will bottle them on the same day and conduct a blind taste test w/ myself, my Father-in-law, and a couple of friends who particularly like this recipe.

This yeast produces a lot of spicy phenols, so if there is little to no difference in flavor, a clean yeast like 1056 should be no problem. I will probably do a split batch of my Pale Ale recipe to confirm this empirically. I will update this thread with results.

 

[Jboggeye]

please do! I have the exact same system as you with the exact same questions. My "room temp" is 72-74 after a week or two in the temp controlled freezer, and I would love to know what that really does.

 

[Acidjazz54]

Subscribe. Please let us know your results.

 

[joel4482]

I decided to conduct a split batch experiment to test this out for myself. I have a 10 gal batch of Saccharomyces' Belgian Pale Ale boiling now which I plan to split w/ 5.5 gal in a bucket and 4.5 gal in a BB carboy. I will ferment both until Friday 4-15 in a temp controlled fridge (decided to move my Johnson controller to the big fridge until I slow down a little!) and then I will pull the carboy out and let it finish at room temp between 75-80*F while the bucket remains at 68*F for the remainder of fermentation (3 weeks total). I will bottle them on the same day and conduct a blind taste test w/ myself, my Father-in-law, and a couple of friends who particularly like this recipe.

This yeast produces a lot of spicy phenols, so if there is little to no difference in flavor, a clean yeast like 1056 should be no problem. I will probably do a split batch of my Pale Ale recipe to confirm this empirically. I will update this thread with results.

I think that is a great idea. You can read all sorts of info and get lots of opinions. The best way to get the answer you are looking for is to test it for yourself. The most important info and opinions are those of the people drinking your beer. That is why I love to split batches in half and test different variable.

 

[pjj2ba]

Good for you on answering your own question with an experiment!!!!!

I can almost guarantee you that they will taste different. What I can't guarantee is which one you will prefer. I wouldn't be surprised if it is a split decision. This is why it is best to test it for yourself. Figure out what processes give the flavors YOU like, and do it that way.

As others mentioned, temperature is not as critical as during the initial fermentation, but it still is important.

I brew a whole bunch of lagers in the winter/spring to drink in summer. As a result I'll typically have 3-6 kegs of lagers that will sit in the basement at around 65 F for 2-3 months while waiting to go on tap. I've never had off flavors from this. Sometimes, not as clear as I would like, but no off flavors. My O'fest's can go 5 mo. under these conditions and be great.

 

[beerspitnight]

We had our celebration ale in secondary all last week while my brew partner was back in the US for Spring Break. He racked from primary before he left and tossed in 2oz of whole leaf cascade into the secondary. He got back to Beijing on Sunday night and said the beer had some white "stuff" floating around on top and there was a paint thinner smell to beer. Not good. At first I thought we had an infection, and it might be, but I was also wondering if the "smell" was due to a rise in temperature within his apartment while he was gone. I don't think it would have gotten above 75F during the day. Perhaps we made vinegar? We used Safale 04 for this brew.
I am heading over there tomorrow to check it out and see if it is drinkable. I suspect not. I am also waiting on a pic of the fermenter to see what is going on. Needless to say this was our first brew and I am a bit disappointed. But live and learn I guess.

 

[pjj2ba]

It is probably fine. Often you can get a little bit of yeast activity as they eat up the little bit of food that comes in with the hops. This usually results in some little white patches on the surface of the beer.

There are many threads of people who thought their beer was ruined, but stuck it out and waited, and ended up with great beer.

 

[Jboggeye]

+1, don't worry yet, there's no reason to

 

[emjay]

We had our celebration ale in secondary all last week while my brew partner was back in the US for Spring Break. He racked from primary before he left and tossed in 2oz of whole leaf cascade into the secondary. He got back to Beijing on Sunday night and said the beer had some white "stuff" floating around on top and there was a paint thinner smell to beer. Not good. At first I thought we had an infection, and it might be, but I was also wondering if the "smell" was due to a rise in temperature within his apartment while he was gone. I don't think it would have gotten above 75F during the day. Perhaps we made vinegar? We used Safale 04 for this brew.
I am heading over there tomorrow to check it out and see if it is drinkable. I suspect not. I am also waiting on a pic of the fermenter to see what is going on. Needless to say this was our first brew and I am a bit disappointed. But live and learn I guess.

He could be smelling acetaldehyde, for which there are various reasons it might occur, but the main one is taking it off the yeast too early. It's possible that it will clean up if you give it a bit more time, but if he's smelling it THAT strongly, I really can't say. How long did you leave it in the primary for, and at what temperature?

But... does it smell like paint thinner or does it smell like vinegar? Vinegar is a pretty distinctive and easily recognized smell - I'm not sure how your partner could be confused.

pjj2ba is right that the white stuff doesn't sound particularly alarming, but I don't know how he could seemingly ignore the smell part - anything intense enough to be described as paint thinner would seriously concern me.

Please post back tomorrow when you get a chance to smell it again and let us know if it IS a vinegar smell. You should taste it as well - at worst it just won't taste super pleasant, and I've personally found that sometimes, young beers can give off a pretty vinegary aroma that isn't even detectable in the taste. So every observation you can make and include in your post would be helpful - even that picture.

Other than that though, RDWHA... commercial beer (for now). It'll either be good or it won't be, and if it isn't, you just need to look at your sanitation practices and try again. If it DOES turn out that you've made vinegar, fruit flies are a likely culprit and you probably don't want to brew around them.

 

[flatfour64]

I am also subscribing to this thread to read results from the OPs experiment. Currently I ferment controlled and then store bottles at a room temp that can be 68 in the winter and 74 in the summer. It all boils down to the fact that I need a second storage or "lagering" fridge!

 

[jamnw]

subscribe: my 3rd brew ever is a Munich Helles, that accidently got to 75F this weekend, for about 24 hours. Moved it to another location that is 64F. Best I can do for now.
Funny, I was wondering the same thing last night when I was moving the carboy, then a big storm hit and I couldn't get online to post this exact same question!!!

 

[emjay]

I didn't read all responses - not enough time - but one thing you didn't mention in your post is raising the temperature at the end for the purposes of increasing attenuation. I apologize if this has already been discussed, as it's not exactly ground-breaking stuff, but it's such a damn useful (and in my opinion, important) technique that I figured I'd mention it anyways, just in case.

When I'm going for a really dry beer, I'll try to knock another few gravity points off by increasing the temp by 1-2°F per day, sometimes up to the low-mid 80's - and in rare and extreme cases, the high 80's and even low 90's! At this point, the yeast is really doing such a marginal amount of work that any off-flavors potentially produced will be absolutely negligible (most of the time, if timed right), and yet that added bit of dryness will noticeably enhance the character of the beer. Seems like a no-brainer to me if you're working with a style that benefits from high attenuation.

Then I'll often cold-condition it. And although I'm fairly sure it should at least have some small effects on flavor in addition to (and largely because of) the yeast dropping to the bottom and clearing the beer up, I'm not nearly as confident that it will have a noticeably positive effect as I am about raising temps to further dry out a beer. So I wouldn't mind seeing your conclusions.

 

[beerspitnight]

He could be smelling acetaldehyde, for which there are various reasons it might occur, but the main one is taking it off the yeast too early. It's possible that it will clean up if you give it a bit more time, but if he's smelling it THAT strongly, I really can't say. How long did you leave it in the primary for, and at what temperature?

But... does it smell like paint thinner or does it smell like vinegar? Vinegar is a pretty distinctive and easily recognized smell - I'm not sure how your partner could be confused.

pjj2ba is right that the white stuff doesn't sound particularly alarming, but I don't know how he could seemingly ignore the smell part - anything intense enough to be described as paint thinner would seriously concern me.

Please post back tomorrow when you get a chance to smell it again and let us know if it IS a vinegar smell. You should taste it as well - at worst it just won't taste super pleasant, and I've personally found that sometimes, young beers can give off a pretty vinegary aroma that isn't even detectable in the taste. So every observation you can make and include in your post would be helpful - even that picture.

Other than that though, RDWHA... commercial beer (for now). It'll either be good or it won't be, and if it isn't, you just need to look at your sanitation practices and try again. If it DOES turn out that you've made vinegar, fruit flies are a likely culprit and you probably don't want to brew around them.

I don't mean to hijack this thread...
Fermentation in the primary was for 12 days - racked to secondary and added the hops. It has been in the secondary since the 31st. The temp during the primary would have been between 63-66 at most (ambient), probably closer to 63. The beer tasted good when we racked it to the secondary, save for the loss of some hop aroma (hence the dry hop).
No fruit flies out and about yet.
I'll post back tomorrow (racking to kegs tonight) with taste, smell and pics.

I think we are done with racking to the secondary. We should be getting our immersion chiller in on Saturday (although those Chinese always say, "yes, yes, no problem, we deliver maybe on Saturday." - then it shows up on Tuesday) and shouldn't need to rack for clarity.
Thanks again guys and I will post again tonight (your morning!)