CoolBrew Fermenter Facts

Frequently Asked Questions and Tips  
1.) Why do I need to keep my wort cold while fermenting?
2.) Will the Cool-Brewing Fermentation Cooler fit my Carboy or Fermenter?
3.) How do I keep my Cool-Brewing Fermentation Cooler cold?
4.) What is the ideal temperature for fermentation?
5.) Do I need to use water with ice to cool?
6.) How often do I need to add ice?
7.) Can I move my Fermentation Cooler while full?
8.) Can I  use my Cooler for other purposes?


1.)    Why do I need to keep my wort cold while fermenting?

      Controlling the temperature of actively fermenting wort has a major impact on the flavor of the finished beer.  Fermenting above the desired temperature range can produce fruity off flavors, esters and harsh fusel alcohols.  The typical recommended ale fermentation ranges are 59-72 degrees F.  It is not an easy task keeping  an actively fermenting beer this temperature in a warm  room!  Add in the fact that active fermentation can raise the temperature 10-15 degrees F for a typical 5 gallon batch!   

2.)   Will the Cool-Brewing Fermentation Cooler fit my Carboy or Fermenter?            

      Our cooler bag will accommodate most 5 gallon and 6.5 gallon carboy and fermenting buckets.  The size of our cooler bag is 26.5” x 21.5”  (HxD).  As the size of carboy’s and fermenters can vary please measure yours prior to ordering if you have any concerns.

  The size of a standard 6.5 gallon fermenter bucket is: 22”x18”

  The size of a standard 6.5 gallon carboy is 20.5”x12.5”


3.)    How do I keep my Cool-Brewing Fermentation Cooler cold?

      You can keep your fermentation cooler cold just as you would keep any cooler cold.  Just add ice, ice packs or anything cold to keep reach and keep the desired temperature.  A great method is to use plastic bottles of ice.  This way you can just refreeze them once they thaw and there is no mess.    


4.)    Do I need to use water with Ice to cool?

      No, Unlike like a swamp cooler typically used by home brewers to lower fermentation temperatures water is not required!  You can however use water if you would like as our bags are designed to be 100% waterproof it is just not necessary to keep your fermenter cool in most cases.

5.)    What is the ideal temperature for fermentation?

      Normal ale fermentation temperatures range from 68 to 72 degrees F or (20 to 22 degrees C).  Typically your yeast used will list ideal temperatures ranges on the package.

      Normal Lager fermentation temperatures range from 48 to 55 degrees F.

6.)    How much ice does it take to lower temperatures?

      The amount of ice needed will vary based on individual circumstances however our testing has shown a rough average as follows for a 5 gallon batch of lager:

      2 ice 2-liters lowered actively fermenting wort  an average of 11 degrees  for 24 to 36 hours before thawing.

      3 ice 2 liters lowered actively fermenting wort an average of 15 degrees for 24 to 48 hours before thawing.

Therefore  roughly 1 ice 2-liter will lower fermenting wort around 5 degrees for a 5 gallon batch.  Again this is roughly and results will vary.

7.)   Can I move my Fermentation Cooler while Full?

     Do not move your Fermentation Cooler while full.  Remove Fermenter or Carboy prior to moving. Also do not to let children play in or around cooler.

8.)   Can I use my Cooler for other purposes?

      Of course you can. Many homebrewers find other useful purposes for our coolers however we accept no liabilities if used in a manner other than specified.