Boil-Off Rate

[blisster]

What do you guys typically have for a boil-off rate per hour?

I know this depends on several factors, mostly on how vigorous the boil is and the surface area of the kettle...

I started with a little over 7gal yesterday. After a 60 minute boil and chiller/cooling loss ended up with 4.5gal in the fermenter.  Kettle trub loss was quite minimal due to the hop basket.

I ended up boiling off almost 2gal gal in one hour. I did have one spill over but that shouldn't account for much of that 2 Gal..

Even with a very hard boil, 2gal/hour seems way too high?!  My kettle is only a 9Gal OBK one so the surface area isn't that big..

[Chris Craig]

I get 4 litres/hr with a gentle boil.  You'll get 4% shrinkage due to cooling too.  So, if you had the same boil off rate as me, that's 7 gal to start - 1 gal boil off - 4% = 5.64

You gain almost nothing from a vigorous boil, in my opinion. 

[brynn]

I was conditioning my 10 g aluminum kettle and boiled off 7L of water in an hour on Monday. I remember reading somewhere that if it is windy you'll get a higher boil off. Beersmith has a dilution tool that you can use to determine the top amount of water to add. If I boil off too much I would just add some bottled water to bring it back up

[Chris Craig]

That's a great idea. I've never thought of that before.

[jamie_savoie]

I also do that when I overshoot too much my gravity.  The dilution tool is another great tool in beersmith

[Jake]

Man, you guys and your beersmith tools ... I'm not even sure I own a hydrometer