Keggle evaporation rate

[bmickey]

After about 10, 5 gallon batches in my converted 15 1/2 gallon keg setup I still seem to struggle with my evaporation rates during the boil being high. Some of this is leftover wort, hops, sediment (1/2 gallon or so)

Yesterday I brewed a IPA with a 16.6lb grain bill. I started out with an initial volume of 8 gallon with hop additions totally 5.5oz, my beersmith recipe was supposed to give me 6 gallons of wort to ferment. At the end of the boil I stirred hard, set for 10 minutes, and drained through my counter flow chiller. In total I got a little under 5 gallons wort to ferment. Other times I have brewed other recipes with 7 gallons initial volume and still netted 5 gallons!

Should I boil with a lid partially covering the top?

How hard is your boil rolling?

Any advice greatly appreciated.

 

[jerryalan]

Best advise I can give you is (assuming you're using a burner) to always set the pressure knob at the same setting, make sure your tanks aren't close to empty (close to empty tanks have less pressure), and keep the wind away from the burner flames (set up some sort of wind blocker if you're brewing outdoors). Doing this has helped me realize that I have a 1.7 gallon per hour boil-off rate. You can then plug that into Beersmith and it'll adjust your sparge volume accordingly. I always hit my target volume.

 

[bmickey]

Yes, bayou burner and in my garage with garage door open, little wind. Sounds like you have a pretty decent evaporation rate as well.

 

[jerryalan]

Yeah, it took me a couple of batches to figure it out. It helps a lot if you have a site guage on your keggle too.

 

[bmickey]

I might have to install a site glass, we were just talking about that last night. Did you make yours or buy one?

 

[jerryalan]

I bought one from Bobby_M: http://www.brewhardware.com/