Author Topic: Temp question: How exact?  (Read 1098 times)

Offline DW

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Temp question: How exact?
« on: November 10, 2011, 07:36:58 AM »
Many recipes call for certain fermenation temperatures or temperature ranges.  I've heard that the temperature in the fermenation is a bit higher than the surrounding temperature.  So, how does everyone look at this.............are those fermentation temperature guidelines referring to the surrounding temperature, or do they expect you to consider the inside environment of the fermenting beer?  I tried placing a temperature probe inside the primary to get the exact temperature once for an octoberfest.  This worked miserably, and the beer didn't finish down to the appropriate gravity.  Should we lower the outside temperature to account for the higher inside temperature?????? Hmmmmmm

Offline jimrod

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Re: Temp question: How exact?
« Reply #1 on: November 10, 2011, 08:06:22 AM »
Yes, the fermentation temps are for the actual liquid. Use a thermowell connected to a Johnson or Rancor thermostat and that will turn your fridge or heater blanket on or off to keep the temperature perfect. Try these ebay listings.

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Offline DW

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Re: Temp question: How exact?
« Reply #2 on: November 10, 2011, 08:16:47 AM »
I actually have a thermostat that controls my fridge temps.  Are you saying there should be a probe within the liquid that is connected to the thermostat or do you just modify the temperature in the fridge? 

Offline bo

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Re: Temp question: How exact?
« Reply #3 on: November 10, 2011, 08:19:57 AM »
Just set your fridge temp controller for 3-4 degrees below your fermentation temp for a few days and you'll be fine. After the fermentation slows, bring it up 3-4 degrees and let it finish.  You can go to all of the trouble of putting a probe in your wort, but you risk infection and in the end, it won't really help you that much.

Offline DW

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Re: Temp question: How exact?
« Reply #4 on: November 10, 2011, 08:22:08 AM »
Cool. Appreciate the advice ;D

Online morticaixavier

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Re: Temp question: How exact?
« Reply #5 on: November 10, 2011, 08:41:47 AM »
you can also afix the probe to the outside of the fermenter with some paper towel or bubble wrap around it so that it reads, more or less, the temp of the liquid without actually being in the liquid.
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Offline a10t2

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Re: Temp question: How exact?
« Reply #6 on: November 10, 2011, 09:40:05 AM »
An LCD strip thermometer on the outside of the fermenter is a cheap (~$3) option, and will let you monitor the actual beer temperature.
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Offline tomsawyer

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Re: Temp question: How exact?
« Reply #7 on: November 10, 2011, 12:16:03 PM »
you can also afix the probe to the outside of the fermenter with some paper towel or bubble wrap around it so that it reads, more or less, the temp of the liquid without actually being in the liquid.
+1 this is what I do.

For ales, I ferment in my cool basement and I use a swamp cooler to pull the extra heat out of the fermentation.  By having a larger heat sink, you get less of an increase in wort temp from the heat of fermentation.
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Offline dmtaylor

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Re: Temp question: How exact?
« Reply #8 on: November 10, 2011, 04:53:52 PM »
I set a thermometer on top of the fermenter (I use plastic buckets), and for the first couple days of fermentation when krausen is huge, I assume the actual temperature of the beer is about 2-4 degrees higher than the thermometer.  It's close enough.
Dave

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Offline dogismycopilot

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Re: Temp question: How exact?
« Reply #9 on: November 10, 2011, 06:03:40 PM »
+1 on taping the probe to the side of the carboy, covered in styrofoam, bubble wrap, etc, to insulate

Offline Tristan

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Re: Temp question: How exact?
« Reply #10 on: November 11, 2011, 06:40:42 AM »
You can also put your fermentor in a tote or bin filled with water.  The water level should be up to or close to the wort level inside the fermentor.  You can float a thermometer in that water.  Water is a good conductor so this temperature should be pretty close to the wort temp.  The added benefit is that you can manipulate the water by adding heating (aquarium heater and pump, available at wally world) or cooling (frozen water bottles, etc).  This also increases thermal mass and mitigates wild swings in temperature.
« Last Edit: November 11, 2011, 06:43:00 AM by Tristan »
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Offline dmtaylor

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Re: Temp question: How exact?
« Reply #11 on: November 11, 2011, 08:47:46 AM »
I've done that as well.  It's a really good idea if you need to know exact temperature.  Should be accurate within a degree.
Dave

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Offline denny

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Re: Temp question: How exact?
« Reply #12 on: November 11, 2011, 09:57:56 AM »
An LCD strip thermometer on the outside of the fermenter is a cheap (~$3) option, and will let you monitor the actual beer temperature.

People seem to go to great lengths to do something more difficult!  ;)  The temp strip on a fermenter is remarkably accurate.
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