Boil off rate of a 10 gallon megapot

[stadelman]

I've got a 10 gallon megapot from Northern Brewer. I'm currently brewing over a couple of burners on my stove top. This gets me to a good boil, but not what I would call crazy-vigorous.

Does anyone have a guess as to how many gallons an hour this setup would boil off?

I'm going to actually figure it on my next batch, but I'd like a good starting point.

Thanks!

[bub]

It really so completely depends.... outside temp, wort "thickness", outside humidity, moon phase.
BUB

[UhrigBrauer]

Yeah dude... what boob said, plus the biggest factor I found was the increased surface area of the pot. My boil off goes from a 1 gal/hr to ~1.3 gal/hr. How did I find this out.... well, like a dumbass I though I had enough propane to make it through the whole boil. Instead I ran out 15 min in and had to pour 1/2 my wort into a WIDE stock pot and split the boil on the stove. I think I lost 1.5 gal/hr on that setup. Now I have two tanks.

You could always test it with water and see what your evap rate is approximately. Hell you could add plaid old table sugar to that to make a 1040 sugar wort to simulate beer wort and see how much boils off.

cheers brotha
JC

[Jhwk]

Make a measuring stick. Get a wood dowel, or something similar. Pour in a gallon of water, measure and mark the stick with a sharpie. Ad a gallon, measure... repeat until full. Then, you can do a test boil for one hour and get an idea of what your loss rate is.

Or you could go with the old 10% value... your results WILL vary.

[stadelman]

Thanks everyone!