Evaporation rate of boiling water/wort?

Buying, building and using brewing equipment and apparatus. Product reviews and questions.

Moderator: slothrob

Evaporation rate of boiling water/wort?

Postby pach907 » Sun May 23, 2010 6:41 pm

Does anyone know a formula that I can use to calculate the evaporation rate of boiling water/wort given the size of the brew kettle and temperature of the water. I have a 15 gallon Polar Wear brew kettle, and a camp chef propane 30K BTU burner that will only bring the water up to about 208ºF, or at least thats what my thermometer is reading. I just boiled 4 gallons of water for 60 minutes and lost 1 gallon right down to the ounce to evaporation. This equates to 25% and seems a little high. Any help would be greatly appreciated.
pach907
 
Posts: 9
Joined: Sun Feb 21, 2010 9:18 pm
Location: Anchorage, Alaska U.S.A

Postby conman » Sun May 23, 2010 8:25 pm

really sounds about right to me, I get approximately the same results.

as for a calculation, I think you just came up with your own answer.........
Homebrewing since 1998!
conman
Pale Ale
Pale Ale
 
Posts: 57
Joined: Thu Jul 19, 2007 2:05 pm

Postby pach907 » Mon May 24, 2010 3:14 am

Thanks. I figured as much. I'm a nerd and like to know the specifics on stuff like this.
pach907
 
Posts: 9
Joined: Sun Feb 21, 2010 9:18 pm
Location: Anchorage, Alaska U.S.A

Postby conman » Mon May 24, 2010 8:13 am

is your water actually boiling on the burner? is so, you must be either at a really high altitude or yeah, your thermo is off!.
Homebrewing since 1998!
conman
Pale Ale
Pale Ale
 
Posts: 57
Joined: Thu Jul 19, 2007 2:05 pm

Postby pach907 » Mon May 24, 2010 12:28 pm

I'm in Anchorage AK and I'm about 180' above mean sea level, We've had a really dry spring so far, the garage is at about 20% humidity. I realize there are many variables that effect evaporation such as relative humidity, barometric pressure/altitude, temperature, surface area, amount of heat being applied and soforth. I am attempting to brew some of the recipes in Jamil Zainasheff's and John Palmers book Brewing Classic Styles, and on page 41 it cites an evaporation rate of 15% per hour. I was just wondering where that number came from. Like I said I'm a nerd and enjoy knowing the trivial stuff. Thanks for all the input folks.
pach907
 
Posts: 9
Joined: Sun Feb 21, 2010 9:18 pm
Location: Anchorage, Alaska U.S.A

this is all I could find.

Postby conman » Mon May 24, 2010 2:34 pm

Homebrewing since 1998!
conman
Pale Ale
Pale Ale
 
Posts: 57
Joined: Thu Jul 19, 2007 2:05 pm

Postby pach907 » Mon May 24, 2010 3:22 pm

Holy cow I just had a flashback... for a second or two I had the unnerving sensation of sitting in college che-mystery class haha! The Langmuir equation is dealing with a substance/molecules/granulates immersed in a fluid, absorbing the fluid, be it a gaseous fluid or a liquid fluid. Wow, I haven't heard or seen the term Langmuir in quite a while haha! Thanks for the flashback conman!
pach907
 
Posts: 9
Joined: Sun Feb 21, 2010 9:18 pm
Location: Anchorage, Alaska U.S.A


Return to Equipment

Who is online

Users browsing this forum: Google [Bot] and 4 guests