Fermenting temperature consistency?

[mongoose33]

Had a conversation w/ a local brewer--can't hardly call him a "home"brewer as he's somewhat past that, having brewed for 22 years--and he critiqued my fermentation process. That's ok, I want critiques.

However, his comments seemed...odd to me because I thought what I was doing was more than acceptable.

Once I've pitched my yeast and installed the airlock, I keep my fermenter in my basement. It sits on the concrete floor which to some extent acts as a heat sink, and I have a cardboard box over it to prevent light from getting to it. Right now, after fermentation is complete, the temp of the fermenter is 64 degrees. I suspect a lot of people would like to have a situation like this where the natural environment gives them this temperature.

When fermenting, the temp rises to 68 degrees, maybe to 70, but that's as high as it gets. I'm using S-04 whose listed range of temperatures is 59-75 degrees. So it would seem as I have a comfortable middle of that range.

My local brewer friend says I should sit that fermenter in a vat of water to smooth out the temperature swings. Presumably this would result in a better beer.

I didn't have a chance to quiz him about this--it seems like I have a nearly ideal situation for this, but for him, apparently too wide a temp swing even though I'm well within the state range for S-04.

What am I missing here? Would I produce better beer if damped out that temperature swing? I'd think that eventually the higher temp fermenter would warm the water the fermenter sat in, and I'd still end up in the same place.

Thank you!

 

[Revvy]

If you're only going 4-6 degrees higher and (1) it's in the temp range of the yeast and (2) it swings back down to your base temp of 64 as soon as the biggest, heat producing period of fermentation (3 days after fermentation begins) I doubt if you're going to notice a substantive difference in flavor. We're not talks jumping to or staying at 85 degrees in the heat of summer for 2 weeks or something.

BUT this might be a fun experiment. Split either a 5 or brew a 10 gallon batch, and keep everything equal, and put half in a water tub and the other on the floor and see.

I really don't that only the most sophisticated palate would say there was a difference. You're not cooling your beer down or forcing it to stay in a temp range with water bottles or ice, it sounds like he's only using the water because he things it will slow down the temp changes, since water usually does that.

But Imma kinda thinking that a huge concrete floor heat sink, is going to be even SLOWER to change overall temp than a water bath. We're talking a lot more square feet of something cool doing a good job of holding it's temp.

 

[HLSheppard]

I am currently using the "water bath" technique as I lack a secondary/dedicated fridge to use. While I've been happy with my beers, I ALWAYS realize that (like espresso, my other passion) there is always something to tweak.

Perhaps my palate isn't as sophisticated as others - but then again, I'll never aspire to be a pro brewer, etc.

Learning, tweaking and learning some more...

 

[mongoose33]

If you're only going 4-6 degrees higher and (1) it's in the temp range of the yeast and (2) it swings back down to your base temp of 64 as soon as the biggest, heat producing period of fermentation (3 days after fermentation begins) I doubt if you're going to notice a substantive difference in flavor. We're not talks jumping to or staying at 85 degrees in the heat of summer for 2 weeks or something.

BUT this might be a fun experiment. Split either a 5 or brew a 10 gallon batch, and keep everything equal, and put half in a water tub and the other on the floor and see.

I really don't that only the most sophisticated palate would say there was a difference. You're not cooling your beer down or forcing it to stay in a temp range with water bottles or ice, it sounds like he's only using the water because he things it will slow down the temp changes, since water usually does that.

But Imma kinda thinking that a huge concrete floor heat sink, is going to be even SLOWER to change overall temp than a water bath. We're talking a lot more square feet of something cool doing a good job of holding it's temp.

I'm using BMB's so the fermenter sits on a 'ring' on the base of the fermenter as it's domed. I suspect a vat of water--provided it had greater contact w/ the floor--might improve that a bit as the water would possibly better connect w/ the concrete floor heat sink.

Thanks, Revvy--it just didn't seem to me to be THAT important based on what I'd read, but this guy is pretty good and it just struck me as out of range for what I thought I'd understood.

I might do as you suggest at some point, split the batch. I have a 5-gallon secondary fermenter I no longer use for secondary fermenting (thanks to Brulosopher and people here), so it wouldn't be that hard to do.

 

[blizz81]

In regards to fermentation temperature, I think you'll find over time that what yeast manufacturers list as a range for a given yeast is not necessarily indicative of producing the best quality beer possible using that yeast. I think this yeast, S-04, is a great example of that. It can really rocket off on you if not controlled.


One personal example with S-04 - I used it on a 6.5-7% stout in a fermentation chamber where I had the probe measuring ambient air. This had seemingly been fine up to that point (probably 15-20 batches?) - I had been able to set the controller at about 5-6 degrees less than target ferm temp and though I didn't measure peak ferm temp in all of those batches, those that I did verify with a thermoworks probe directly in the beer generally acted as desired.

The S-04 stout, I set a target of I believe 66-67*F. Came home around the 36hr mark of fermentation to a chest freezer full of blowoff, my blowoff vessel had runneth over. I believe I was a bit past peak ferment at that point as there really wasn't much krausen coming through the tube by then, but measured temp inside the vessel (not on a stick-on thermometer - not saying those don't work but I trust a certified calibrated device + quality probe myself) was 79.5*F.

The other thing, even if you're inside the "indicated range", depending on the yeast, your flavor profile will change. Most people ferment S-04 pretty darn cool to keep it clean. I would think you'd see a fair amount of interesting, fruity esters if you did ferment S-04 at, say, 74*F, or even 70*F.

 

[Revvy]

I'm using BMB's so the fermenter sits on a 'ring' on the base of the fermenter as it's domed. I suspect a vat of water--provided it had greater contact w/ the floor--might improve that a bit as the water would possibly better connect w/ the concrete floor heat sink.

Thanks, Revvy--it just didn't seem to me to be THAT important based on what I'd read, but this guy is pretty good and it just struck me as out of range for what I thought I'd understood.

I might do as you suggest at some point, split the batch. I have a 5-gallon secondary fermenter I no longer use for secondary fermenting (thanks to Brulosopher and people here), so it wouldn't be that hard to do.

Hmm, the water to even out the contact with the floor might have merit.

But the biggest thing really boils down to... is your beer tasting great this way or not? To me it always boils down to 1) How's the beer taste doing this method 2) Is the change in flavor substantial enough to balance out the extra effort involved.... And if it is, can I streamline the process to make doing it easier?

If you ever do the experiment, I would be interested in hearing the results. I think, like I said, any temp shifts within the temp range of that strain of yeast may not be noticeable in MOST beers. Some of that might be detectable in extremely light grainbill/abv beers.

For example I had an issue years ago that popped up with S-05 (which was my goto yeast for years) producing a "stone fruit" flavor in low grav or "light colored" beers. Like peach flavors. It wasn't noticeable in darker beers (at least initially.) I think Safale change the yeast or something...I still used it for darker ales, but then it became prevalent in all their beers so I stopped using it altogether. (I'm starting after couple of years not using it, trying it again to see what it's like.)

So what I'm saying is it may be noticeable in that session or smash you brew, but not in that imperial stout.

interesting topic.

 

[blizz81]

I know a lot of people have had issues with S-05 and peachy / fruity esters here on the forums. (Though it seems they're somewhat held at bay by not fermenting cool)


I guess if there's any takeaway to my blabbering above, it would be to do some searching around here on the forum if / when you want to use a certain yeast strain to find out more about how it behaves. There's a lot more information that can fit on here vs. a yeast packet or vial.

 

[Revvy]

I know a lot of people have had issues with S-05 and peachy / fruity esters here on the forums. (Though it seems they're somewhat held at bay by not fermenting cool)

I know, isn't that funny? We're usually worried about those esters when fermenting warm.

I just started using it again since they changed the packaging, and so far I've only done an IPA with it, figuring the hops would hide it.

When I stopped, BR-97 just started hitting the market, and I've been absolutely happy with using that as my goto neutral ale yeast. I've noticed no off flavors with that one whatsoever.

 

[Puddlethumper]

I'm in there with Revvy that if it's working for you and you're making beer that tastes good then why fool with it? Basically, if it isn't broke don't waste time trying to fix it.

I think that home brewers all too frequently forget that people have been making very good beer in cool basements, cellars and caves for centuries. And yes, absolute temperature control of the fermenting beer is ideal. But temperature controllers and dedicated refrigerators/freezers for fermentation chambers are things we, as home brewers, have only had access to very recently.

Brew on and have fun!
Cheers!