Will Double Crush Improve Efficiency?

I mash in a fine mesh bag (voile), as such, don’t worry about stuck sparges and I’ve been wondering if I could improve my extraction efficiency by double crushing the mashing grains.

Who here double crushes? What has it done for your efficiency? Typically, what can I epect as an improvement, in points?

What is the base efficiency you are trying to improve?

Double crushing will improve your efficiency if your crush isn’t very good to begin with.

I double crush routinely. I don’t have my mill set very aggressively to avoid over-crushing. My efficiency went up when I started double crushing and I still don’t have to worry about producing too much flour. Maybe I should’ve bought a 3-roller mill to start with…

Like most questions that are posted… it depends. Since everyone’s system and procedure will be different, the only way to really tell is to try it for a batch and find out. With that being said, I would guess that your efficiency would improve if your grains are crushed by your LBHS.


If you’re mashing in a bag and controlling your mash pH, you can crush until you see a fair amount of flour and significantly boost your extraction. Also, a short bump in mash temp into the 163-165F range and a 10-15 minute rest will help squeeze out a little more enzyme activity at the end of the mash.

My current effiency is around 75% depending on the crush from the HBS. I’d like to improve is possible.

My O G went up 17% on one batch and 15.5% on another when I double crushed the grains. I’ve got to dig out the instructions and tighten things up a bit.

I typically have HUGE effeciencies. I lay the Blame/credit (depends on how ya look at it eh?) on my crush/grind method. I have one of the cheapest most labor intensive methods possible (cause I’m cheap). I use a Corona mill. I get a good mix of particle sizes but do get a good amount of flour. I batch BTW. Last weekend I brewed Ken’s Home Run Red Ale. I had a 85 % effciency. That is a pretty normal number for me.


The first thing I always look for is that your grains are consistently crushed and all of them easily break apart when touched. Past that you are not going to get much of a benefit from pulverizing it. Set the mill for the proper crush once through and be done with it.