increase boil off rate

My 7 hours RIS boiling marathon got me thinking about increasing boil off rate, is there an easy way to do it in homebrewing conditions, would some kind of exhaust system over BK help?

For a higher boil-off rate:

Use a pot with a wider diameter to increase your surface area.

Use a more powerful heat source.


But why did you boil for 7 hours?

I did a RIS with a 60 minute boil. Is your MLT too small? If not, just use more grain and accept a lower efficiency. And/or use DME to supplement.

Geez.. why did you sparge so much?

Max I'll boil for is 2 hours. You can increase boil off by blowing a fan across the top of the vessel.

And if you boiled that much for that caramel flavor, you could just remove a small portion (like one gallon) and boil it down to 75% of its volume (i.e. down to one quart)

Seems like you wasted a good deal of time, energy, and money...

it was terrible brewing day, i wanted to do 2 beers partigyle style so mashed really thin to got my first big beer but i didnt pull enough points from first run, had to cancel small beer and sparge as usual so i ended up with huge volume i had to reduce, got what i wanted at the end (sg at 1.1) but 6 hours later, fortunately i use NG so no problem with running out of propane and cost NG is nothing i worry about too much (my monthly bill for non heating months is $45-50 and 90-120 for winter, i dont see real change since start brewing)