Evaporation rate - Home Brew Forums

 Home Brew Forums > Evaporation rate

05-28-2011, 12:09 AM   #1
enohcs
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Jan 2008
Washington, DC
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Will water evaporate at a constant volume or a constant percent? Real example: my pre boil volume is 10 gallons, I boil for 90 minutes and finish with 7.5 gallons. How many gallons do I need to start with if I want to end with 13 gallons after a 90 minute boil?
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Matt

05-28-2011, 12:12 AM   #2
Golddiggie

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Dec 2010
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Seriously??

IF you maintain the same boil rate, use the same amount of energy (either electric or gas) to heat the wort, and the kettle is the same size/shape, then you'll lose 2.5 gallons in 90 minutes no matter what your starting batch size is. So, start with 15.5 gallons of wort to get 13 gallons at the end of the boil...

Pretty basic logic here Bubba...
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05-28-2011, 12:56 AM   #3
IronMike
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condescension sucks.

05-28-2011, 02:26 AM   #4
tasq
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Mar 2010
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Quote:
 Originally Posted by IronMike condescension sucks.
Agreed!
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05-28-2011, 02:31 AM   #5
Ohio-Ed

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Nov 2008
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Quote:
 Originally Posted by Golddiggie Seriously?? IF you maintain the same boil rate, use the same amount of energy (either electric or gas) to heat the wort, and the kettle is the same size/shape, then you'll lose 2.5 gallons in 90 minutes no matter what your starting batch size is. So, start with 15.5 gallons of wort to get 13 gallons at the end of the boil... Pretty basic logic here Bubba...
Environmental conditions (ambient temperature, humidity, wind, etc) will play a role also.

05-28-2011, 03:36 AM   #6
Sixstring78
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Mar 2011
Colchester, Ontario
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Quote:
 Originally Posted by IronMike condescension sucks.
Major +1
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