Mash and lauter efficiency question


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Trial Member
Feb 16, 2013
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This is my second AG brew. I did a belgian wit with an adjunct mash. Most things turned out well but I would like to know what happened here. I had a pre boil volume of 8.2 gal with a gravity of 1.041. I was shooting for a 90 minute boil but cut it off at 70 minutes because I hit my final gravity goal of 1.046. with a volume of 7.3 gallons. What does this tell me about my system and how do I tweak it so I can get to a 90 minute boil? I have set my brew house efficiency at 65%.

I mash in a 10 gallon Rubbermaid cooler and boil in an 8 gallon kettle.
Mike K
It could be your efficiency is higher and it could also be your equipment profile needs adjustment. If you had more volume than expected at the same gravity, that means your efficiency is higher. I would double check the boil off rate, mash tun dead space, etc.

The brew feature and associated log entries will help shed light on the subject. For more information about how the system calculates efficiency and what brew log entries are required, see this FAQ:
less stuff in your mash. your conversion efficiency is better than expected. if your target is a 5.5 gallon end at 1.046, that means a pre boil gravity at 8 gallons is in theory, 1.032-ish. Now, given that, if you were boiling for 70 minutes and you only got down from 8.2 to 7.3 gallons, you'll want to kick that boil in gear in order to get it down to 5.5 in 90 minutes