Now Im offically a brewer! But one small problem: Temp Control

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Well-Known Member
Jan 2, 2008
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Houston, TX
Last night was the first time that ive brewed. Everything went as planned and was a success, as for as I know. The only thing that I ran into is keeping the temperature down for the fermenter. I would like to stay away from making my house one expensive refrigerator. Since I live in houston we dont really have a winter (its currently 65 outside right now), so i need a way to keep it cooler. This morning it was reading 70 degrees but I know it will change as the day gets warmer. I put it in the coldest room in the house with an oscillating fan pointing on it full blast. Any ideas? I thought about putting it in a spare tub with cool water (no ice) and also with the fan. Other than that it was a success and I noticed the air lock started to very slightly bubble every 5 sec or so this morning. :ban:
use a washtub or similar and put your fermentor in a water bath it will pull heat away from it more efficiently than just the fan and also keep the temp steadier throughout the day.
Simplest cooling method is probably a tub of water, with a wet towel wrapped around the fermenter and extending into the water. Then blow the fan on it. I think if you search for 'swamp cooling' you'll find info about it (though I may be remembering wrong).

Congrats on the first batch! :mug:
When you check the temp are you checking it at floor level where the fermenter is? I have found that from floor level to even waist or chest high can be roughly a 5 degree difference.
I was just going to chime in with the same thing- a washtub with a tshirt over the fermenter (or a towel) with the ends in the water to "wick up" water. Add a fan to blow over it, and it'll cool it. Make sure you have a stick on thermometer (not under the water, but closer to the top of the fermenter) to monitor the temp INSIDE the fermenter. If the ambient temperature is 70, inside the fermenter might be 75 or more.

If you want to get "fancy", get out my Yooper lagerator in my gallery. It's just an igloo cooler ($20) with a stryofoam lid I just to put on it. I can add water and frozen water bottles and have it nice and cool, even cold, this time of year here. I keep a floating thermometer in the water bath- because the inside of the carboy would be about the same temperature in there.
^^ Yeah I have a sticky thermometer that is attached to the glass carboy. I also take a separate reading by setting another thermometer right next to the fermenter.
Thanks guys for the speedy response. Ill have to do that as soon as I get home from work.
for what it's worth, I don't think you'd have much trouble fermenting at 65 degrees. I've done many fine batches in the 65-70 area.
^^No the carboy was reading 70. The outside ambient temp was 65. I was just worried that when the day progressed it was going to get warmer and so would my brew.
MikeFlynn74 said:
Damn that sucks- I dont know if you guys will ever have a winning season

If your talking about temp....yes I agree.

If your talking about the texans.....wait till next year. We ditched a lot of people (along with a lot of injuries) and had a better season this year. So next year, will be a good year.
Kush -

Go Texans! Temp control is impossible in the summer and difficult in the winter down here. Here's what I've found so far.

1) +1 Swamp Cooler. Instead of my tub, I picked up a Rubbermaid storage bin, one of the 20 gal ones. Put your primary in it, cover with a wet t-shirt, and then put a few cubes of ice on the top in the morning and in the evening. That method got me down about 5F below ambient. You'll get a few more degrees cooling with a light fan breeze, maybe 8F below ambient.

2) +1 Yooper's Ice Cube. I just picked up an Igloo Ice Cube at Walmart for 22 bucks. I don't think they make the 60 qt version anymore since I couldn't find it on the Igloo website, so be careful if you buy online w/o seeing the product. Igloo also doesn't make the model without wheels (Yooper's doesn't have wheels, I recall) meaning that the bottom corner is beveled and may need need to elevate your primary a little. You can wet t-shirt in the cooler or, better yet, make a cool water bath like Yooper recommends.

The big advantage to this method is better heat transfer between your cooling medium and the Primary, more accurate idea of temperature inside the fermenter (due to improved heat transfer) and you don't need to worry about the t-shirt drying out.

You can even add a some bleach to kill the mold that will form. I've been thinking about super-gluing the drain cap closed so it cannot leak.

3) I saw an idea on BYO to take an old dorm fridge, open the door, and build a styrofoam box like a second fridge compartment. I haven't tried it yet, but will do it soon. I found 1/2 styrofoam at Lowe's for about 10 bucks a sheet. I'd plan on making everything double-ply for a better R-value. You can check out Dow's website for more info on Styrofoam. 1/2" gets you R-3 and 1" gets you R-5, I think.

Great stuff here:

4) Pick a different yeast. I don't know much on this topic, but something I read on WLP001 mentioned that it stays somewhat neutral at higher temps, meaning less banana and less wretched (!) esters. I've also heard that you can let WLP550 just rip. I've actually got some going right now, in a Cherry Wheat, and it stopped working when the temp dropped to ~60-62F. My LHBS fellow said some folks have been so bold as to put a secondary with WLP550 on top of the clothes dryer to shake and heat things back up a little.

Hope this helps. If you find out anything more, make sure to post it.
I found a corner in my house that with keeping my thermostat at 70 and a fan I got my fermenter to 67-68. It seems that the yeast are active, but not too active. Is this a good temp? Im a big fan of "if it isnt broken dont fix it" so if this is a good temp to stay constant at, let me know.

On another note; this hobby has already sucked me in, that I went to my lhbs and purchased another secondary (and bavarian hefeweizen ingredients) to start another brew once my primary frees up. I think i have a :mug:
Son of fermentation chiller is totally the way to go. I built one before I started my first brew, and it works great. I usually change the two ice jugs once a day or once every other day, depending on the temp.

If you're planning on doing two batches at a time, or one in primary, another in secondary, I'd extend the length given in the son of fermentation chiller plans by a good 9-12 inches or so. I had problems getting my carboy to fit in there next to my ale pail.

Cheers! :mug: