Fermentation Temperature Commercial vs. Hombrew... What Gives?

So I have noticed a trend recently, not just on this forum, but on others as well. Homebrewers usually suggest fermentation temps 62-66 degrees when fermenting ales. This doesn't seem to depend on what strain either. For example, WLP 007 has a suggested temp of 65-70 degrees from White Labs. A few folks have said they started off low like 60 or 62 and ramped it up. (Some have even noted stalled fermentations)

Commercial breweries obviously have interest in quick fermentation, which is why for the Black IPA recipe I am looking at Stone ferments at 72 degrees. Others seem to fall in line with 68 being quite the norm.

What I am trying to get at is, do homebrewers think they are gaining an advantage fermenting cooler that is actually noticeable? Can you really notice a difference in 65 and 68 in the finished beer? Commercial breweries make great beer at 68 so I just don't see why the rule of thumb is always colder.

BreezyBrew said:

So I have noticed a trend recently, not just on this forum, but on others as well. Homebrewers usually suggest fermentation temps 62-66 degrees when fermenting ales. This doesn't seem to depend on what strain either. For example, WLP 007 has a suggested temp of 65-70 degrees from White Labs. A few folks have said they started off low like 60 or 62 and ramped it up. (Some have even noted stalled fermentations)

Commercial breweries obviously have interest in quick fermentation, which is why for the Black IPA recipe I am looking at Stone ferments at 72 degrees. Others seem to fall in line with 68 being quite the norm.

What I am trying to get at is, do homebrewers think they are gaining an advantage fermenting cooler that is actually noticeable? Can you really notice a difference in 65 and 68 in the finished beer? Commercial breweries make great beer at 68 so I just don't see why the rule of thumb is always colder.

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I wouldn't say it's the rule of thumb - it just depends on the yeast strain and what you're going for. For example, take a yeast like Conan from the Alchemist. It probably ferments best and attenuates better around 66-68 F or so, but some of the most desirable "peachy" characteristics and aromatics that can be obtained from it are reportedly at a lower fermentation temperature around 60-62 F. The best thing I can say is to do a fair bit of research before you decide what temp you're going to ferment your yeast at and have a game plan. For example, I just pitched a belgian strain on an IPA the other day. I want it to have some noticeable esters, but not overwhelmingly so to blunt the hop profile. In this case I'll be fermenting around 66-68 F or a tiny bit higher depending on the temp in the house which will likely leave me with the profile I'm desiring in the finished product.

Research, baby. It's not just for nerds anymore.

...Just kidding, it totally is. Embrace the nerditude.

My thoughts are that pitch rates may have something to do with it. Starting out on the cool side helps reduce some of the by-products produced during the early stages of yeast growth. Commercial breweries may pitch at levels where this is not as great of an issue and can therefore start fermentation at a higher temperature.

Also, commercial breweries probably measure the temp in the center of the fermenter. Most homebrewers measure it at the sides. The middle can be a few degrees warmer. I can definitely tell the difference between us05 at 60 vs 68.

Breezy....

I recently started fermenting at lower temperatures. Just prior to that, I brewed several high gravity beers, which was new for me. I've usually always brewed beers in the 4-6 % range, but these ranged from 7-9.5%. All of them were very hot and alcohol forward. I keep the house at an even 68 degrees and feel confident that was where the beer fermented. Reading some of the threads here, books, other internet sites... It became clear that the higher fermentation temp was creating fussel and other undesirable flavors in the beer. What was also stated was, that while the temp in the house may well have been a steady 68, the yeast activity in the fermenter was most likely raising the temp in the fermenter by several degrees, which meant that there was really no way of knowing what the temp in the fermenter was - that it might have been quite a bit higher than 68.

The first beer in the fermentation chamber experiment is clearing now. I'll be kegging it today and should be drinking it in a couple of days. It's ABV is 7.5%, so it should be a good example. I will say that I racked to secondary on Saturday and the taste test I took was really good. I'm looking forward to seeing if there really is a difference. Especially since the folks on HBT almost preach fermentation temps as being the number 1 consideration when brewing a beer.

The other thing I've read is that a beer should stay on the yeast cake for awhile longer than I was keeping it there. From what I got, the early, more agressive - simple sugar, fermentation should always take place in a fermentation chamber at a controlled temperature. After that week or so, remove the fermenter and allow the beer to warm up to the 70 degree range to bring the yeast to a more active state. At that point, it will clean up the beer and get rid of anything that might cause off flavors. I was racking off of the yeast at 2 weeks usually. I'm leaving it on the yeast cake for a few more weeks before racking.

I'll see the results soon enough as I have 5 beers that I'm running through the whole process.

I know I didn't answer your question, but I've asked similar questions here and on other boards. As a result, I created a fermentation chamber and began the process outlined above. Hope this info helps.

I have also read that a commercial brewer's tall conical fermenters result in increased pressure (weight?) on the yeast which suppresses the flavor expression. So their 68 degree fermentation might be similar to a homebrew scale fermentation at 65F wrt ester and other yeast derived flavor.

Commercial brewerys have jacketed fermenters cooled with a glycol solution so they can have precise temperature control throughout the fermentation period. Time is critical to them too as when the fermenter is full, they can't start another batch so it's a money issue for them to get that fermentation over quickly.

Homebrewers usually have much less control of the temperature so it works best for us to start our fermentation cooler and not worry about the temperature rise because that rise will put us quite near the best temperature range for the yeast. An extra fermenter for us is pretty cheap so if our fermenter is full, we can just buy another one. Not so simple for a commercial operation because of cost and space. Their buildings can only hold so much equipment and unlike plastic buckets, theirs can't be stacked when not in use. Adding another fermenter for them means adding to the building, getting the permits, replumbing everything.

BreezyBrew said:

So I have noticed a trend recently, not just on this forum, but on others as well. Homebrewers usually suggest fermentation temps 62-66 degrees when fermenting ales. This doesn't seem to depend on what strain either. For example, WLP 007 has a suggested temp of 65-70 degrees from White Labs. A few folks have said they started off low like 60 or 62 and ramped it up. (Some have even noted stalled fermentations)

Commercial breweries obviously have interest in quick fermentation, which is why for the Black IPA recipe I am looking at Stone ferments at 72 degrees. Others seem to fall in line with 68 being quite the norm.

What I am trying to get at is, do homebrewers think they are gaining an advantage fermenting cooler that is actually noticeable? Can you really notice a difference in 65 and 68 in the finished beer? Commercial breweries make great beer at 68 so I just don't see why the rule of thumb is always colder.

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I try to tailor my fermentation temperatures to the yeast strain I'm using, and how it's been suggested to be used.

With a chico strain, I've found cool 60s to my liking. Fermentation progresses fairly quick and the beers have been yeast neutral. I have occasionally allowed my fermentors to naturally rise in temp after a few days for batches that I want to encourage to finish low; while others I've tried to peg in the low 60s for the duration so they stay neutral and don't over-attenuate.

Some english strains I've taken the approach of pitching at 64 and allowing to rise to 68F over 24-48 hours; hold there for 48 hours; and slowly bring back down to 64-65F for the remainder. The idea to encourage some ester formation, but not have the yeast over-attenuate. The fermentations in this schedule have worked well and the beers have been good. Did it make a huge difference? I really don't know, but I liked them.

Most of my saisons have been pitched at 68-70F, wrapped in a blanket, and allowed to rise naturally to 85+F for the duration. Again, good beers.

My belgians have mostly been pitched at 64F, unwrapped, and allowed to rise anywhere from 68-72F. Sometimes I have to put a little blanket around the lower half of the fermenter to encourage a little extra temp.

I like notty and scottish ale yeast really cool - 55-58F. I try to peg s04 at 64F for the duration. And antwerp ale I try to keep at 68F for the duration.

I definitely tailor my fermentation schedule to the yeast strain and what I'm trying to accomplish, however, most of my chico beers are fermented anywhere from 61-65F (usually around 63-64F)

stpug said:

I try to tailor my fermentation temperatures to the yeast strain I'm using, and how it's been suggested to be used.

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Yeah, after re-reading my post, I really wasn't clear. I did mean typical ale yeast, and not really ones that are yeast driven like Hefe's and Saisons. I try to do what you do as well.

As for my fermentation vessel, I have a temperature controller and chest freezer. I tape my probe to the outside of the carboy, and cover it with bubble wrap so the probe doesn't read the ambient temp. When I first started, I used a thermowell with the probe, but that didn't work very well, the swings got into the low 40s ambient, and that dropped the yeast out of suspension.

The nice thing about the controller is that you can dial in the temp you would like.

smccarter said:

The other thing I've read is that a beer should stay on the yeast cake for awhile longer than I was keeping it there. From what I got, the early, more agressive - simple sugar, fermentation should always take place in a fermentation chamber at a controlled temperature. After that week or so, remove the fermenter and allow the beer to warm up to the 70 degree range to bring the yeast to a more active state. At that point, it will clean up the beer and get rid of anything that might cause off flavors. I was racking off of the yeast at 2 weeks usually. I'm leaving it on the yeast cake for a few more weeks before racking.

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This anectodal advice has grown in this hobby due to homebrewers under-pitching/aerating leading to unwanted flavor compound production in the first place. It is unnecessary if you are pitching the correct amount of yeast and using pure oxygen to provide optimal levels of dissolved O2.

Once the beer is at terminal gravity and done fermenting, it really does not get any more "done" by sitting on the yeast cake for another 3 weeks. A short conditioning period may be beneficial, but the whole "off-flavor clean up" by what is in reality mostly dormant yeast is really overdone.

g-star said:

This anectodal advice has grown in this hobby due to homebrewers under-pitching/aerating leading to unwanted flavor compound production in the first place. It is unnecessary if you are pitching the correct amount of yeast and using pure oxygen to provide optimal levels of dissolved O2.

Once the beer is at terminal gravity and done fermenting, it really does not get any more "done" by sitting on the yeast cake for another 3 weeks. A short conditioning period may be beneficial, but the whole "off-flavor clean up" by what is in reality mostly dormant yeast is really overdone.

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So many experts on HBT... it's really difficult at times to tell which one is the true expert... .

My rule of thumb is ... pick a process and give it a good try. If it works, continue. If not, try something else. I'm working the process I've outlined for now, but will give yours a try some time later on. I'm sure that the correct pitch rate is the proper way to handle this situation, but I don't have the proper equipment at hand to determine the "exact" number of yeast cells I'm pitching. I do use a calculator and always create a starter on the bigger beers.

Thanks for the advice though. It's all very good and much appreciated.

BreezyBrew said:

What I am trying to get at is, do homebrewers think they are gaining an advantage fermenting cooler that is actually noticeable? Can you really notice a difference in 65 and 68 in the finished beer? Commercial breweries make great beer at 68 so I just don't see why the rule of thumb is always colder.

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I am a homebrewer. As such, I'm free to do things that commercial breweries can't. I can batch sparge, or ferment at lower temps if I feel like it. I do what experience has proven to me works for me. I revel in the lack of constraints that commercial brewers have. And just because someone sells beer doesn't mean that it's good beer. Sure, there are a lot of good commercial beers out there but there are a of of sucky ones, too.

I've assumed it's because they probably pitch very accurately and the pressure from the beer in such large fermenters changes things up. Two things that most homebrewers don't deal with. Although I'm sure more than a few are very anal about their yeast.

OK, I have another theory. How about homebrewers only have a vague idea what their actual temps are when they pitch?

The temps are different in different places in the fermentor during lag phase. It depends on lots of things, high/low, inside/outside and how quickly it was cooled, to name a few.

Once the fermentation gets started, everything gets stirred up pretty quickly. Problem here is that the disparate temps are likely to average out faster than the ferm chamber can keep up.

This would cause the beer temp to change quickly, depending on how good your guess was for the average temp. Yeast hate that.

If you start low and sneak up on it, that’s the safe way to go. The fermentation starts gradually. If you start in the middle, and it goes up, that’s bad. If you start high and it goes off like a rocket, that’s very bad.

Commercial fermentors have glycol belts around the middle, which induce convection currents. Plus these things are freakin’ huge, so their temperature regulation is really tight. So when their fermentation takes off, it’s faster , more uniform and way more predictable.

Wynne-R said:

OK, I have another theory. How about homebrewers only have a vague idea what their actual temps are when they pitch?

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Good point. Just looking at the ferment temp by itself without also considering pitch temp and yeast pitch rates is like reading a book, but skipping every other paragraph. All three go hand-in-hand.

Also, home brewers don't have the time pressured production schedule that the commercial guys might face. A few extra days fermenting because we pitch a few degrees below target temp and start it at the lower end of the optimal range for the strain to obtain a cleaner flavor used doesn't cost us like it does the big guys.

The pressure generated by a tall thin uni tank will certainly suppress ester formation, so you need to go slightly warmer to get the same profile. Although how much will depend on a lot of other thing.

Another thing to consider is that some big commercial breweries also start their ales really low (a certain big craft brewery around here starts their ales at <60 F). It is for the same reason we do it, pitch a lot of yeast, keep it cool for the lag phase to limit yeast reproduction, the let it rise to ideal temps to produce the desired ester profile.

No you have my 2 cents,

Chickens

LBA4ME said:

I have also read that a commercial brewer's tall conical fermenters result in increased pressure (weight?) on the yeast which suppresses the flavor expression. So their 68 degree fermentation might be similar to a homebrew scale fermentation at 65F wrt ester and other yeast derived flavor.

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Not only that, but since their fermenters use spunding valves instead of airlocks, many commercial brewers ferment under slight pressure as well, adding to this effect. The pressure inhibits the production of several compounds that are typically considered off flavors, most notably esters and fusel alcohols. This can allow very "clean" and fast fermentation at higher temperatures. How the pressure changes the flavor profile is highly dependent on the yeast strain though, and in some cases it can cause a significant increase in sulfur production.

FWIW pressurized fermentation is pretty easy to do at home with a keg and spunding valve.

To put it simply, commercial breweries brew their beer differently than homebrewers do. What works for one might not work for the other.
Fermentor design, cooling, pitch rate, oxygenation, yeast health/repitching, ingredients, timetable for sales, etc., etc.

All great points. It sounds like there are a lot of fermentation differences that make commercial breweries brew the way that they do. If home brewers had the same type of situation, they may brew like that also. It would make sense for them to. I know one thing, this thread really makes me want to try fermenting in a pressurized vessel!

BreezyBrew said:

I know one thing, this thread really makes me want to try fermenting in a pressurized vessel!

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This might interest you if you haven't seen it yet.

https://www.homebrewtalk.com/f13/closed-system-pressurized-fermentation-technique-44344/

+1 to the pressurized fermentation. Commercial breweries often use pressurization to reduce off flavors, and they can ferment at higher temperatures which means less $$ to control fermenter temps.

Not to mention, they have very advanced filtration systems which remove the yeast and help finish a beer sooner.

OTOH, a home brewer has other advantages....MORE control over temp (MUCH less volume to keep cool) and no "bottom line" that dictates what and how you brew. This is the reason why breweries also have pilot systems....so they can brew things outside of the business plan.