Author Topic: keeping fermentor cool  (Read 930 times)

Offline cjberquist

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keeping fermentor cool
« on: August 29, 2013, 03:00:24 PM »
hi guys,
im new to brewing and have my first batch started of a wheat beer.
im in the process of keeping it cool and was wondering whats the best way to check the temp of the wort and not temperature around the bucket. its in a refer at the moment but would like to keep an eye on the liquid itself instead of measuring the temp of the refer thanks guys!

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Re: keeping fermentor cool
« Reply #1 on: August 29, 2013, 03:16:53 PM »
So you have it in a fridge with an external temp controller?

I have not had a problem just leaving the probe in the fridge.

If I am misunderstanding and you just mean how do I monitor the wort temp, I am fond of the 2 buck stick on LCD thermostrips. surprisingly accurate and cheap
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Jonathan I Fuller

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Re: keeping fermentor cool
« Reply #2 on: August 29, 2013, 03:18:51 PM »
+1 to thermostrips.
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Offline ynotbrusum

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Re: keeping fermentor cool
« Reply #3 on: August 29, 2013, 03:24:50 PM »
Well the best way is probably using a thermowell that dips into the wort and allows a flexible thermistor to slide down inside the thermowell below the level of the wort.  Also, a sanitized thermometer would work, but I don't want that in my wort while it is fermenting.  If using a swamp cooler, I use the external water temperature and figure the beer to be anywhere from 4 - 8 degrees higher at full krausen when the yeast are chugging along.

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Re: keeping fermentor cool
« Reply #4 on: August 29, 2013, 08:26:02 PM »
Those stick on strip thermometers. The specific heat of water is much higher than air, which means you can feel confident that the surface of the fermenter is close to the temperature of the beer rather than surrounding air.  Or you could get fancier and put a digital probe thermometer on the wall and cover it with insulation and tape, but then a thermowell might be easier.
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Offline reverseapachemaster

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Re: keeping fermentor cool
« Reply #5 on: August 30, 2013, 08:43:31 AM »
I tape the temperature probe to the outside of the fermentor. It isn't as precise as a thermowell but as long as you have a consistent process you can create a controllable and repeatable process.
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Offline cjberquist

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Re: keeping fermentor cool
« Reply #6 on: August 30, 2013, 07:33:04 PM »
thanks for the quick replies! at the moment im using the fridge without the external controller , i keep the temp in the fridge around 60 but can be a pain in the a$$ constantly watching it . so that answered my ? though i was jus worried the stick on thermometers would get all screwed up and measure the temp of the air in the fridge instead but sounds like im gunna go buy one

Online morticaixavier

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Re: keeping fermentor cool
« Reply #7 on: August 30, 2013, 08:00:08 PM »
thanks for the quick replies! at the moment im using the fridge without the external controller , i keep the temp in the fridge around 60 but can be a pain in the a$$ constantly watching it . so that answered my ? though i was jus worried the stick on thermometers would get all screwed up and measure the temp of the air in the fridge instead but sounds like im gunna go buy one

another super cheep tool that might help ease the trouble till you get a controller is a timer. One of the kinds that you plug into an outlet then plug a light into or similar. It takes a little trial and error to get the timing right but eventually you can learn to set it to keep the beer more or less stable.
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Offline Jarhno

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Re: keeping fermentor cool
« Reply #8 on: September 10, 2013, 09:31:18 AM »
I'm pretty sure that the wort will always try and equalize to the temperature of it's ambient air temperature (I.E. the fridge temperature).  It may take awhile, but if the fridge is a constant temp. then the wort will eventually reach that temperature and stay there. If the fridge warms up or cools down then the wort will follow that temp. change (just very slowly).


That all being said: one thing to think about is if you have a very vigorous fermentation, then the temperature will probably be higher in the fermentor due to all that activity going on.

Of course I could be wrong about all this due to error in trying to recall physics classes and the Great John Palmer.
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Re: keeping fermentor cool
« Reply #9 on: September 10, 2013, 10:19:01 AM »
I'm pretty sure that the wort will always try and equalize to the temperature of it's ambient air temperature (I.E. the fridge temperature).  It may take awhile, but if the fridge is a constant temp. then the wort will eventually reach that temperature and stay there. If the fridge warms up or cools down then the wort will follow that temp. change (just very slowly).

That all being said: one thing to think about is if you have a very vigorous fermentation, then the temperature will probably be higher in the fermentor due to all that activity going on.
Your second part answered the first. It will follow of course, but most fermentations will be several degrees above ambient because fermentation generates heat. In my large fermenter (60 gallon barrel) it's often 10 degrees above ambient even with slow fermentation at low temperatures (50F).
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