Question: Fermentation Temp Control

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eurc51

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I've been brewing for about 2 years with pretty consistent success and have never worried much about temperature. Basically, I keep my house at 66 degrees (F) when brewing. However, the thermometer on my carboy always reads 76 - 78 during the first day of fermentation for an ale and usually drops down to 70-72 by the 2nd and 3rd day. I'd like to take a more active approach in managing my temperature, but I'm not sure how. I'm guessing that I need to manage the temp on the carboy and not the room temperature of my house, correct? For example, if the yeast says 57-75 degrees, this is the temperature range I need to maintain on the carboy thermometer and not my room temperature? Can anyone recommend a good approach? I've read a few threads about using a tub of water. Can anyone comment?

Thanks,

emu
 
I use a tub from Lowes of the type that is commonly used to ice beverages at picnics.
It was pretty cheap (less than $15?) as I recall.

In the summer I swap frozen coke bottles every 12 hours to keep the beer temperature below room temperature.
In the winter I use an aquarium heater to raise the temperature.

I'm in the process of switching to an Ice Cube cooler, but it doesn't fit my Ale Pails - I need some 6.5 gallon carboys.
 
if money is not an issue for you there is a more accurate and more expensive way to control the temp of your beer. i recommend a Ronco 2-stage ETC, fermwrap, chest freezer, and thermowell setup. the thermowell is just a long metal tube that is sealed at one end and goes into your beer. this allows you to place the temperature lead of the ETC into the wort without getting it wet. this will allow you to get very accurate readings of the actual wort temp. you may need to sandpaper the temp lead down a little to get it to fit. don't worry this wont hurt anything. the 2-stage ETC allows you to control the on/off of two different items based on temperature. they can be both heating elements, cooling elements, or one of each its up to you. each element can have its own on/off temp and temperature variance. both the freezer and fermwrap just plug right into the ETC and it does the rest.
 
So fermentation is exothermic, and in some cases (big beers, busy yeast) it can be VERY exothermic. The 6-8 degree rise you're seeing fromt ambient air temperature is on the high side from my experience.

The question you want to be asking is: Is the temperature range suggested on a yeast packet the actual fermentation temperature, or the reccomended ambient air temperature? This is something I've been wondering since I started brewing...
 
The question you want to be asking is: Is the temperature range suggested on a yeast packet the actual fermentation temperature, or the reccomended ambient air temperature? This is something I've been wondering since I started brewing...

its the actual fermentation temp.
 
I also wondered the same thing and thought it wa the ambient temp. well after some research and podcasts I found out it's the actual temp fo the wort.

what I've been doing is chilling my wort down to 60-65* and pitching the yeast. then leaving the carboy in the basement. temps usually go up to about 65-68* during fermenation. when my fermentation stops/slows down I take the carboy upstairs where the ambient temp is 68-70* and I let it finish off while it raises in temp due to ambient. of course this may not work well for people without a basement and/or differnet climates than mine

I'd like to get a mini fridge or a side by side and make a fermentation chamber but that's not in the cards just yet. I like the idea of taking the wort temp to where I wnat it to be, pitching and then not having to worry about and walk away.
 
I use the bucket of water technique, and it works great. When my basement warms up a bit more, I use a bucket of water + a tshirt around the carboy + fan on the Tshirt. Tshirt wicks up water, fan evaporates water, and you get a nice 6-8 degree temp drop in the carboy.
 
I use one of those ~20 gallon plastic barrels that HDB mentioned. I wrap it in a folded up old bedsheet, add a few inches of water in the bottom, a blanket over the top, and swap out frozen water bottles to keep the water bath temp in the low 60's. I don't have carboy thermometers, so I don't know for sure what the actual fermentation temperature is, but I imagine that it is much closer to a surrounding water temp than it would be to a surrounding air temp.
 
+1 on the ranco 2 stage controller..... It's like shooting fish in a barrel.I have a chest freezer for my cooling stage and a hair dryer for the warming stage.... Works very well ... As a bonus I can now brew year round in addition to having the ability to brew lagers and belgians.Spend the money.... You won't be sorry.
 
if money is not an issue for you there is a more accurate and more expensive way to control the temp of your beer. i recommend a Ronco 2-stage ETC, fermwrap, chest freezer, and thermowell setup. the thermowell is just a long metal tube that is sealed at one end and goes into your beer. this allows you to place the temperature lead of the ETC into the wort without getting it wet. this will allow you to get very accurate readings of the actual wort temp. you may need to sandpaper the temp lead down a little to get it to fit. don't worry this wont hurt anything. the 2-stage ETC allows you to control the on/off of two different items based on temperature. they can be both heating elements, cooling elements, or one of each its up to you. each element can have its own on/off temp and temperature variance. both the freezer and fermwrap just plug right into the ETC and it does the rest.

I use a very similar approach. Differences are that I have a wine refrigerator that I scored on CL that nicely holds a carboy and I don't use a thermowell, but tape some bubble wrap to the side of the carboy (not overlapping the fermwrap) and tuck the the temp probe between the carboy and the bubble warp. It keeps the beer at the desired fermentation temperature.

Cheers,
Glenn
 
Something simple that can help is to make sure your temperatures at pitching are low. Some people will pitch at 75-80 degrees, and be surprised when their fermentation temperatures are that high. If you pitch at 80 degrees, and the yeast starts fermentation, it'll be really hard to get it down.

So, my recommendation is to chill the wort to 60-64 degrees. Then pitch the yeast and allow the temperature to rise to your desired fermentation temperature. That seems to help with temperature control right from the start.
 
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