Exact Ferment Temps Matter?

[Jordan Logo]

Hello all!

Just brewed a sample one gallon batch and pitched with White Labs San Diego Super Yeast. According to White Labs the optimum ferment temperature is 65-68°F. Unfortunately my house runs right around 72°F. Is this a problem? Also, what amount of temperature is usually okay to play with around the recommendation? I know you don’t want to go over by 10°, but I’m guessing 5° or below wouldn’t matter.

Thanks!

 

[BrewnWKopperKat]

Unfortunately my house runs right around 72°F. Is this a problem?

Yeast will produce different flavors in different temperature ranges. For my small batches, 72°F ambient would result in 73-75°F fermentation temperature. That is outside of White Labs recommended range - it may produce a beer you enjoy.

https://www.experimentalbrew.com/podcast/brew-files-episode-59-keeping-cool offers a number of ideas for temperature control.

One approach I've been using for a while with small batches is to put the carboy into a 35-40 qt cooler filled with water and close the lid. To ferment at 65-68°F, I will keep the water temperature around 64°F for the first couple of days.

 

[myndflyte]

I would try to do something to control temps. With a 1 gallon batch, temps can also swing easier than a 5 gallon bath, which could also affect yeast flavors. So having it in a water bath will help prevent those swings.

 

[McKnuckle]

The simple, inconvenient answer is that yes; fermentation temps do matter. This is frequently stated by experienced brewers as one of the top 3 most important things to focus on in brewing to achieve quality and consistency.

A 5 degree Fahrenheit difference is significant for some yeasts, devastating for others, and nearly irrelevant for others still. So, it does depend. But absent these specifics and the knowledge to manage them, control your fermentation temperatures.

 

[cactusgarrett]

68°F versus 72°F likely won't matter. You might notice a difference in a 65°F versus 72°F comparison. However, as alluded to above, if your ambient temperature is 72°F, during active fermentation (depending on how "active"), you're likely experiencing 75°F in the beer itself.

 

[Jordan Logo]

The reason I ask is because I’ve been digging deep into Brülosophy’s website, and while some of the time fermentation temps have some difference in taste, it seems like most of the time it honestly doesn’t matter. And when the study shows that they were able to pick the odd beer out, he states it could’ve been by random chance.

I’ve been wanting to invest in ways to really dial in my ferment temps but after reading that most of the time the beer is indistinguishable, is it really worth $200+?

 

[McKnuckle]

If it's indistinguishable to YOU, then it won't matter. I think it boils down to that. Only your own brewing experience will show you if it matters.

If you are in doubt, you can keep asking, and most people will tell you that it does matter to them. Some people will shrug it off. Such is the nature of literally any human activity. I don't mean to denigrate those folks - but not everyone cares about best practices and tastes/interests are all over the place. What kind of brewer do YOU want to be?

I will say, though... people who claim that fermentation temperature matters are not just trying to make the process more complicated or to show off their techniques. They're being honest.

So if I were you, don't spend money on it now. Ferment in a way that is convenient and see what you think about the end product. I certainly didn't make investments in temp control early on. But when I did, it was a game changer along with kegging, water treatment, yeast starters, and keg fermentation. But I'm getting ahead of things!

About Brulosophy: I definitely enjoy the site. But if we took everything that Brulosophy xBmts have deemed "insignificant" and decided that none of them mattered, I guarantee that our beer would be generally mediocre to poor. I would argue that there is no pride to be gleaned by ignoring literally centuries of collective learning in the craft of brewing. And fermentation temperature is something that literally every brewery in the world pays a great deal of attention to.

 

[Jordan Logo]

If it's indistinguishable to YOU, then it won't matter. I think it boils down to that. Only your own brewing experience will show you if it matters.

If you are in doubt, you can keep asking, and most people will tell you that it does matter to them. Some people will shrug it off. Such is the nature of literally any human activity. I don't mean to denigrate those folks - but not everyone cares about best practices and tastes/interests are all over the place. What kind of brewer do YOU want to be?

I will say, though... people who claim that fermentation temperature matters are not just trying to make the process more complicated or to show off their techniques. They're being honest.

So if I were you, don't spend money on it now. Ferment in a way that is convenient and see what you think about the end product. I certainly didn't make investments in temp control early on. But when I did, it was a game changer along with kegging, water treatment, yeast starters, and keg fermentation. But I'm getting ahead of things!

About Brulosophy: I definitely enjoy the site. But if we took everything that Brulosophy xBmts have deemed "insignificant" and decided that none of them mattered, I guarantee that our beer would be generally mediocre to poor. I would argue that there is no pride to be gleaned by ignoring literally centuries of collective learning in the craft of brewing. And fermentation temperature is something that literally every brewery in the world pays a great deal of attention to.

Great input! I definitely will upgrade in the future when I hone in my skills

 

[Jordan Logo]

As far as temp controlling your ferments, I’m guessing a keezer is the way to go? What do people do in terms of limited space, let’s say if you live in an apartment

 

[McKnuckle]

It mostly depends on what you want to brew, and what your fermenter looks like. A 6 gallon bucket, being rather wide, is going to need a full size fridge or a chest freezer (keezer). That can be difficult to fit in an apartment. Also, lifting a full bucket in and out of a deep chest freezer is not much fun.

The key to maximizing space is batch size! I know it's not appealing to some, but a 2.5 gallon batch is great because there are kegs in that size, too, so you can scale your whole operation to match. A 3 gallon plastic carboy fits in a small fridge (not a dorm fridge). Usually, up to two 5 gallon kegs can fit in one too - and you can ferment in those.

One example is the 4.4 cu. ft. Danby fridge.

Barring an actual fridge, people use the "swamp cooler" method, obviously cheap and easy, and good for modestly cooling the beer when ambient temp is a little too warm. That's not really temperature control, but it's workable.

If you have an ambient space that's a bit too cold, you could use a heat-only solution like an electric pad or wrap.

If you want to brew lagers, you need to reliably maintain temps in the low 50s for a couple of weeks. If you will focus on ales, you can choose relatively tolerant yeast strains and leverage a cheaper solution. You need to keep ales under 70ºF for best results (beer temp, NOT ambient).

 

[BrewnWKopperKat]

What do people do in terms of limited space, let’s say if you live in an apartment

I used the closed cooler idea when I did some small space brewing a number of years ago (and I still use the approach when I brew).

Two additional resources.

• Brew Files - Episode 59 - Keeping Cool

• Given the limited space of an apartment, what do you do to maintain a steady fermentation?

The second is part of a series of articles on small / apartment / condo brewing.

late addition: https://old.reddit.com/r/Homebrewin...crash_limited_space_and_money_method/el8w64c/

 

[Jordan Logo]

It mostly depends on what you want to brew, and what your fermenter looks like. A 6 gallon bucket, being rather wide, is going to need a full size fridge or a chest freezer (keezer). That can be difficult to fit in an apartment. Also, lifting a full bucket in and out of a deep chest freezer is not much fun.

The key to maximizing space is batch size! I know it's not appealing to some, but a 2.5 gallon batch is great because there are kegs in that size, too, so you can scale your whole operation to match. A 3 gallon plastic carboy fits in a small fridge (not a dorm fridge). Usually, up to two 5 gallon kegs can fit in one too - and you can ferment in those.

One example is the 4.4 cu. ft. Danby fridge.

Barring an actual fridge, people use the "swamp cooler" method, obviously cheap and easy, and good for modestly cooling the beer when ambient temp is a little too warm. That's not really temperature control, but it's workable.

If you have an ambient space that's a bit too cold, you could use a heat-only solution like an electric pad or wrap.

If you want to brew lagers, you need to reliably maintain temps in the low 50s for a couple of weeks. If you will focus on ales, you can choose relatively tolerant yeast strains and leverage a cheaper solution. You need to keep ales under 70ºF for best results (beer temp, NOT ambient).

Yeah I actually just scaled down to 1 gallon batches! I’m using a 3 gallon fermonster. It’s about 16” tall, 9” in diameter. I’m trying to find a mini fridge that would work... you think a 4x4 is the smallest I could go?

 

[Novacor]

As far as temp controlling your ferments, I’m guessing a keezer is the way to go? What do people do in terms of limited space, let’s say if you live in an apartment

https://www.morebeer.com/products/cool-brewing-fermentation-cooler-bag.html

I use one of these and am very happy with it. Frozen 2L water bottles can bring the temp inside the bag down into the low 60's. I swap out the bottles twice a day until the krausen falls, then I let it warm itself up to room temp for the remainder of the fermentation. When I'm not actively keeping it cool, the insulated bag helps protect the fermenter from the day/night temperature swings in my apartment.

I don't have to worry about a messy swamp cooler, and the bag folds up flat and can store just about anywhere while not in use. As another bonus, the bag is water tight and will contain any blowouts you might have.

 

[Kee]

Having a fermentation chamber will give you more flexibility, since many yeast strains are finicky about temperature. But there are many that do just fine at room temperature or above, especially Belgian strains and saisons.

 

[chewyheel]

https://www.morebeer.com/products/cool-brewing-fermentation-cooler-bag.html

I use one of these and am very happy with it. Frozen 2L water bottles can bring the temp inside the bag down into the low 60's. I swap out the bottles twice a day until the krausen falls, then I let it warm itself up to room temp for the remainder of the fermentation. When I'm not actively keeping it cool, the insulated bag helps protect the fermenter from the day/night temperature swings in my apartment.

I don't have to worry about a messy swamp cooler, and the bag folds up flat and can store just about anywhere while not in use. As another bonus, the bag is water tight and will contain any blowouts you might have.

I second this whole heartedly. I have one as well and love it, and it would certainly work well in a small space.

 

[LittleRiver]

I picked up a large(ish) wine fridge from Craigslist for $75, bought a reptile heat mat from Amazon for about $15, and put together a temp controller based on an Inkbird ITC-1000 (for about $20).

There are other controllers that don't require any wiring or assembly, such as the Inkbird ITC-308.

 

[mulletmaster]

This would not apply to your current situation but for your next batch you could try using one of the kveik yeast strains. They have a much higher temperature range that are purported to not have any off flavors.

 

[jack13]

The reason I ask is because I’ve been digging deep into Brülosophy’s website, and while some of the time fermentation temps have some difference in taste, it seems like most of the time it honestly doesn’t matter. And when the study shows that they were able to pick the odd beer out, he states it could’ve been by random chance.

Keep in mind, though, that he uses a methodology designed to guard very carefully against incorrectly concluding the variable, like ferm temp, had an effect when in fact the results were due to random chance. Not a criticism at all; he's employing what's used in science.

But the downside of this method is that, by guarding very carefully against making that kind of error, you increase your chance of making the other type: Concluding the results were due to random chance when in fact the variable DID have an effect*. In "real science", that's the price to be paid because the other type of error is much worse to make.

That's in real science, but is it the worse error in homebrewing? Depends on the situation, but I'd say usually not. Sure, if there were a very expensive piece of equipment that is purported to make better beer, then, yes, I'd want to be very confident the results of that triangle test were not just random chance before I went out and bought it. But if it's something like whether dropping in 2 cents worth of gypsum helps bring out hop flavor in a IPA, I'd settle for less confidence.

To stick with that example, let's say brulosophy found that out of the 20 people, 13 were able to distinguish the difference between the beer with the gypsum and the one without, but that only reached a significance level of 8%. The conclusion would then "have to" be, assuming the usual 5% criteron were used, that gypsum doesn't matter. But is that appropriate? What you're kind of saying** is "I'm only about 90% sure gypsum works, so I won't use it." Again, it makes sense in science to say "I'm only about 90% sure there's a real effect here, so I must conclude there isn't." because you REALLY don't want to claim you've found a real effect and be wrong about it. But in homebrewing?

*it's worth noting that the type of statistical tests used for the kind of data collected in brulosophy exbeeriments is especially prone to this kind of error.

**only kind of, stats nerds ...I'd love your thoughts, but know I'm aware of the liberties I'm taking.

 

[Parrothead1]

The reason I ask is because I’ve been digging deep into Brülosophy’s website, and while some of the time fermentation temps have some difference in taste, it seems like most of the time it honestly doesn’t matter. And when the study shows that they were able to pick the odd beer out, he states it could’ve been by random chance.

I’ve been wanting to invest in ways to really dial in my ferment temps but after reading that most of the time the beer is indistinguishable, is it really worth $200+?

Brulosophy experiments with two different fermentation temperatures, but they are both temp controlled, so temp is steady throughout the entire process. They are not getting the swings that you get with no temp control, higher and lower temps(other than raising slowly after 2-3 days) cause problems.