Keggle Boil Off Rate

So tommorow I use my keggle for the first time, and am VERY excited! I am looking to make a double batch of stout, but am wondering the boiloff rates you guys are noting for an hour long boil.

I figure I can fit 5.25 gallons of beer per fermenter (6.5 gallon carboys, correct me if i can fit more or less), and as said will be boiling for an hour. What should I look to get outta the mash for my Boil Volume?

THanks guys!

I boil off about 1.75 gallons per hour in Utah. It is very arid here though and I would expect it to be much less in an humid environment.

Good point, for the record im in Southern Ontario, and it is supposed to be slightly muggy tommorow and about 26 celsius. Not sure the conversion to farenheit, but its pretty warm for us.

I only boil off about 1-1.25 gallons an hour in Wisconsin. It depends heavily on the atmosphere and your burner.

I think Wisconsin will be closer to my atmosphere then Utah. Would it be safe to say then that I should start out with 5.25 x 2 (for both fermenters), and add another 1.25 for boiloff? That would give me 11.75 gallons to start, does that sound unreasonable?

I start out with 12 gallon boil and end up with about 9.5 gallon of wort after all is said and done. It also depends how close your valve is to the bottom of the keggle.

Rockweezy said:

I start out with 12 gallon boil and end up with about 9.5 gallon of wort after all is said and done. It also depends how close your valve is to the bottom of the keggle.

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With a pick up tube it does not matter where the valve is as long as the tube is almost touching the bottom.

It also depends on amount of hops, amount of break material & how vigorous the boil is. I suspect everyone is going to have a different boil off rate which is going to change like the wind.

I think I will assume 1.25 Gallons over the hour. I am also running a pickup tube, not a valve (yet). Thanks for your help guys! Now if anyone knows an answer to my other thread in this forum (about oatmeal stout) that would be amazing!!! Cant wait to try the keggle tommorow!

I get about 1.25g in Middle TN

1.5g in MO

1.4g just this weekend in CT.

1.) Why not use 5.5 gallons? I use 6.5 gal carboys and do 5.5 gal batches without any blowoffs or other issues.

2.) My keggle has an 18% boil off rate, when I have it at standard set up. HOWEVER - the rate is more dependent on where I have the burner throttled than anything else!! I can vary it from 13% to 20% depending on how much energy I'm applying to the keggle. I suggest you measure your own boil off rate. Yours will depend on lots of factors, notice how everyone who's posted is posting something different.