Temperature Control Basics

[Yreval]

I often hear brewers here mention "temperature control" as one of the variables that improved their homebrew the most.

I'm kind of a noob, and I've just been putting my fermenters (for ales) down in my basement where it's 69-75 degrees.

It's worked well for me so far, but I know a lot of people seem to suggest slowly stepping up the temperature from the low 60s to the low 70s during their fermentation, depending on the yeast. I could probably manage this if I got a thermometer and put together a little water bath in the future.

What do you guys do to control temperature? Do you have any cheap solutions or suggestions on how to approach the subject?

 

[marvinsjunk]

A lot of people use a swamp cooler and this is how I used to keep temps down until I got a dedicated chest freezer and temp controller. Just put water in a large tub and rotate out a few frozen water bottles twice a day for the first 3-4 days of fermentation. You can also put a t-shirt or towel over the fermenter to wick up water and put a fan on it. This provides some additional evaporative cooling. Not very precise but can still result in a noticeable improvement.

 

[Rockn_M]

A swamp cooler is probably one of the easiest and cheapest solutions.

You can also get a Johnsol controler with a chest freezer. This is what I do and it has worked very well. It's a little more expensive but you don't have to worry about adding frozen bottles to help keep the temps down.

 

[mrgrimm101]

I also ferment in my basement. I put my buckets right on the concrete floor, which seems to help keep it somewhat cooler. Get a fermometer for your primary. It's like a thermometer that is a sticker that will stick right to the side of a bucket. Also, I have a thermometer hanging in the room so I know the ambient temperature, as well as the temperature of the beer (using the fermometer.)

You can make a "swamp cooler", which is simply a big tub to fill with water, then place your fermenter in the water and add ice (or freeze water in some 2 liters) to bring the temperature down slightly. However, I would test this out and see how much ice you will need to keep the water temp where you want it.

These tubs seem to be popular for this purpose:
http://images.plumbersurplus.com/images/prod/1/United-Solutions-TU0085-rw-209586-318792.jpg

 

[Yreval]

Get a fermometer for your primary. It's like a thermometer that is a sticker that will stick right to the side of a bucket.

Does this go on the inside of your carboy? I use opaque buckets so this might not be the best option for me. If you put it on the outside I have to wonder if it's more representative of the ambient temperature or of the liquid within.

 

[mrgrimm101]

No it goes on the outside. I use buckets, so with the flat surface it sticks no problem. I've tried putting one on a glass carboy, but it didn't stay because it's not really a big flat surface (mine has lots of ridges/ribs) that keep it from sitting flat.

I would imagine that it is representative of the temperature of the beer within. I guess I'm not 100% positive about that though.

 

[JimRausch]

I don't remember who, but a couple years ago someone posted a little study on the forum where they checked the temp of the wort vs. temp listed on the fermometer on the plastic bucket. It was within a degree or two. Another post was temp. of wort vs. temp. of the swamp cooler water. That was close too.
So, for me the obsessive fool that I am, I have a thermometer checking roomtemp, a floating one in the swamp cooler. and a fermometer on the bucket. I tend to rely on the floating one because it's easier to read than the fermometer.

 

[Yreval]

Thanks for the tips, guys!

 

[pfgonzo]

I don't remember who, but a couple years ago someone posted a little study on the forum where they checked the temp of the wort vs. temp listed on the fermometer on the plastic bucket. It was within a degree or two. Another post was temp. of wort vs. temp. of the swamp cooler water. That was close too.
So, for me the obsessive fool that I am, I have a thermometer checking roomtemp, a floating one in the swamp cooler. and a fermometer on the bucket. I tend to rely on the floating one because it's easier to read than the fermometer.

I have an internal thermowell to measure the center wort temp, as well as a fermometer sticker on the outside. They are usually right on each other, and certainly less than a degree difference.

I happen to prefer refrigerators over chest freezers for temperature control, especially when monitoring internal wort temperature the way my system is set up. I think chest freezers are too powerful, and result in larger temperature swings/carry over. I can lager just fine in a fridge, and depending on where I place it, I can even freeze a keg solid if I feel the need.

 

[Clonefan94]

My basement usually stays pretty cool all year. In the winter it's impossible to raise it much above the low 60s. In the summer, my air runs constantly so is usually around 68. I get by with simply freezing a couple of 2 quart jugs of ice. I set that next to my fermenter and wrap a towel around it. Then after a day or so, I swap it with a fresh ice jug. This usually has my beer sitting right at 64 during fermentation. I use the stick on thermometers and have tested them with a thermopen and it's within a degree.

Obviously my method won't work for everyone, but if you ambient temp is 70 or below, this simple method would probably work well.

I am going to invest in a col brewing cooler soon. Mainly for the cold crash aspect. I have a large chest freezer tha always has a couple of extra frozen jugs of water. This seems like the most cost effective way to crash since my wife is finding more uses for the downstairs fridge than just my beer.


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[wdprice3]

Going to hijack this thread for a related question - I have my fermentation bucket in a water bath (horse bucket). Fermometer on the outside of the horse bucket is staying between 66-68F. Yeast strain is SafBrew T-58 (59-68F). Am I correct in assuming that the temperature of fermentation should be close to that of the water bath? I know that yeast activity will increase temperatures 5-10F above ambient air temperature, but since the plastic is a poor insulator, the temperature of the two liquids should be fairly similar due to the heat dissipation. I'm going to start adding some frozen bottles of water to knock the temperature down a few degrees (it's been cool here the last 2 days with indoor temperatures in the high 60s low 70s, but warmer weather is returning, thus indoor temperatures in the mid 70s). Thanks

 

[JimRausch]

Going to hijack this thread for a related question - I have my fermentation bucket in a water bath (horse bucket). Fermometer on the outside of the horse bucket is staying between 66-68F. Yeast strain is SafBrew T-58 (59-68F). Am I correct in assuming that the temperature of fermentation should be close to that of the water bath? I know that yeast activity will increase temperatures 5-10F above ambient air temperature, but since the plastic is a poor insulator, the temperature of the two liquids should be fairly similar due to the heat dissipation. I'm going to start adding some frozen bottles of water to knock the temperature down a few degrees (it's been cool here the last 2 days with indoor temperatures in the high 60s low 70s, but warmer weather is returning, thus indoor temperatures in the mid 70s). Thanks

The fermometer on the outside of the swamp cooler is probably closer to environmental temp. than the temp of the water. Take the temp. of the water in your water bath. That should be within a degree or two of your actual fermentation temp.

 

[wdprice3]

The fermometer on the outside of the swamp cooler is probably closer to environmental temp. than the temp of the water. Take the temp. of the water in your water bath. That should be within a degree or two of your actual fermentation temp.

Thanks, but I'll have to respectfully disagree, as the water bath temperature has been the exact same as the fermometer temperature over 6 readings during the last 24 hours.

 

[ChelisHubby]

Several people have tested and put in a different thread how the temp of the water bath was only 1 degree cooler the the center of the fermenter. That said measure a square Ice chest I think Iglou or a similar company makes. that will give you the insulation so you only change water bottles as in 12 ounces every 12 hours after primary fermention is done which is roughly 3 to 5 days . during primary fermentation you will need twice the bottles more or less. Steady fermentation temps are important to the yeast so they are not stressed as they work. The larger the volume of water and the more insulated from the outside the better as a good rule of thumb. after 10 days to 2 weeks then you can slowly let the temps creep up to help the yeast Finnish the job. forgive my pee poor typing as I am slightly drunk damned home brew.