Cool Brewing Fermntation Chamber / Fermentation Temp Control

Mashing
1

Hi, everyone.

First off, thanks so much for past advice. It’s really helping us brew better beers and understanding the often ambiguous instruction and technical detail of the processes. In the end, we’re brewing according to our system’s requirements and restraints, which is the wisdom that comes with experience and patience.

But! We are having a lot of trouble controlling ferm temps and it’s driving us mad. This is the one roadblock that we just can’t seem to break through. And we do not have the means presently to invest in a techno-geek cooling system, hence the Cool Brewing query.

So, judging from our own experience with our system, these are our details:

The room we use to ferment is generally at 70-72 degrees. Good temps to rouse the yeast awake, but we have consistently seen our fermenter temps jump from 68 degrees to 78 degrees once fermentation ramps up. I know this is typical, and I’m reassured because the jumps are very consistent with all the beers we’ve brewed.

We recently purchased a Cool Brewing chamber and will experiment with cooling techniques (adding/subtracting ice packs). But, with so much liquid, it will take hours to cool down. How do we anticipate this rise in temps and get our cooler temps right?

I assume we add the fermenter to the cooling chamber with the cool packs, so that the ambient temps in the cooler drop and as the yeast ramp up and warm up, the temps in the chamber and fermenter stabilize. Is this correct? I fear that the pitch temps, let’s say 68, will decrease and the yeast will get sluggish.

I also assume that if a fermentation vessel is in a room that is at 64 degrees, let’s say, and the wort is cooled to 64, then the yeast will without fail raise to 70+, then drop back to the room’s temp once all activity has ceased. And this is, as I understand, not good for the beer. Temperatures have to be controlled throughout. I assume that means lowering the ambient temps to match the increasing wort temps. This is a balancing act, and one I’m investing a lot of time to figure out.

Is this the normal procedure? Monitoring temps like this, actively and vigilantly? Do I have to sit at home staring at the thermometer for 36 hours to get it right?

Another question I have is, and this is purely historical, how did brewers ferment their beers (even in cool temps like in winter or in caves) and get good tasting beer (was it good tasting?) without temperature control? It would be stand to reason that the yeast should already, through natural selection and genetics, withstand the ups and downs of the first crucial days of fermentation.

I love brewing, and dedicated to making good beers, and I would appreciate any help here. and please forgive me for reiterating past queries and concerns. I’m hoping to get help with our concerns, not general concerns.

Thank you!

Christophe

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[quote=“Pastamassima”]
Another question I have is, and this is purely historical, how did brewers ferment their beers (even in cool temps like in winter or in caves) and get good tasting beer (was it good tasting?) without temperature control?[/quote]

I think that most historical beer is nothing we’d find very appealing now. But back then, they had nothing else to compare it to, and it had alcohol. That was enough.

3

[quote=“Denny”][quote=“Pastamassima”]
Another question I have is, and this is purely historical, how did brewers ferment their beers (even in cool temps like in winter or in caves) and get good tasting beer (was it good tasting?) without temperature control?[/quote]

I think that most historical beer is nothing we’d find very appealing now. But back then, they had nothing else to compare it to, and it had alcohol. That was enough.[/quote]

I figured as much. I take it refrigeration and bacteria/yeast control/discovery played a big part in that.

4

Like you I do not have a proper fermentation chamber just yet and I have to make do. What I do is cool my wort down to the lower end of the yeasts range before I pitch, and then set my fermenter in a large bucket of cold water(one of the rope-handle style). I change out ice packs in the water in the morning, and again when I get home from work for the first few days. This has kept my fermentation temps well within range, and pretty consistent so far. After a few days I stop adding ice packs as much and let the temp rise to around 68-70 to let the yeast finish up.

I’ve noticed that it is much easier to control the temp during fermentation if the starting/pitching temp is lower. :cheers:

5

I use swamp coolers like the Dr describes above except mine are igloo cube coolers. I use frozen water bottles to lower the temp.

I have a plate chiller and well water that generally gets my wort into the low 60s in summer and mid 50s in fall, winter and spring. Then my fermenters go into the swamp cooler. If it’s an ale I use 2 12oz water bottles morning and evening like DrShroom. If it’s a lager I use a combination of 1 and 1 1/2 liter bottles to keep the temps where I want them.

It’s not as accurate or easy as a chest freezer with a temp controller but it’s cheap and effective with a little effort. Just like you’ve figured out the characteristics of your brewing system you’ll get a handle on your fermentation chamber with a litte trial and error and your beer will get better with each batch.

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I believe most brewing was done between the months of October and March. At least in the northerly regions. More wine was made southerly.

7

You’ll have to play with your system a bit before you can find the right answer. I’m not sure anyone here can tell you exactly what to do, they can just share their experience. It’ll be a bit of trial and error until you can figure out what works well, but that’s what brewing is all about IMO.

I will say I feel 68 degrees pitching temp is too warm (yeast dependent of course). Pitching temps should be lower than your target fermentation temp. The yeast may start slower, but they will be better for it and less stressed. For most ales, you should be in the low 60’s. For my last batch, I pitched right at 60 and didn’t have any sluggish yeast problems. Additionally, the control of the temperature is most important for the first few days. After that, you can gradually allow the temp to rise to help the yeast finish up and clean up. You don’t really need to keep the temps low through the whole duration, just during the most active part.

My suggestion would be to first find out at what temp you want to ferment the beer at, then cool it to lower than that before pitching. Once it’s there, pitch the yeast and ensure your fermentation chamber is about 5 to 10 degrees cooler than that target temp. Wait for activity to start and see where your beer temp winds up at. During the most active phase, the beer temp could be as much as 8 degrees higher than ambient, so if you’re measuring your fermentation chamber temp as the ambient inside the chamber, you’ll need it to be a bit lower than your target fermentation temp. Add or remove ice packs as needed.

8

Templar: thanks for this. And Danny, I agree wholeheartedly: if our systems were the same and expectations were absolute, we’d be making the same beer. How boring!

I guess my final question is, and please bare with me, this is for my own edification, if I want to ferment the beer at 68 degrees, I should drop the wort after chilling to about 60, banking on the fact that the yeast will increase the wort temps 8-10 or so degrees above ambient. Now, let’s say the yeast does ramp up and hits a maximum of 68 degrees, is my goal to keep it there and swap/add bottles (experimenting, of course, with my own system’s requirements)? I assume the goal of vigilant temp-watching is to make sure the tempts don’t reach above 68.

So, is 68 a cap? Does it still affect/stress the yeast if the temps are moving that high (to 68 from 60)? My first impression was that one should pitch at and keep the temp I want for the duration of the active part of fermentation (3-4 days), then let it rise to clean up. But you’re saying it’s ok for the yeast to REACH 68, allowing me to hold that particular temp for the duration of the active part, without over-stressing?

I just want to make sure that you mean a 68 degree fermentation temp means HIGHEST ACTIVITY temps.

Whew! Thanks again for reading this, and bearing with me. I truly am grateful for this education.

Christophe

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[quote=“Pastamassima”] My first impression was that one should pitch at and keep the temp I want for the duration of the active part of fermentation (3-4 days), then let it rise to clean up.

Christophe[/quote]

^THIS^ is my MO

10

Just keep it under 70 and it will be fine. I try to pitch low then let it rise over a few days. By time it reaches 70 it’s past the three days anyway. In the warmer months use Belgian yeast. Sometimes I use a swamp cooler but I find it a pita. I try to brew with the weather. It’s tough in the heat of the summer, great time to reap your reward though.