I've been trying to fix my efficiency problems for a while now. I normally get 60-65% with grain milled at my LHBS. This time, I took those milled grains and used a friend's mill set fairly small (don't know the gap size). Here's the grain bill I used for this recent recipe...
11 lbs Pale Malt (2 Row) US
2 lbs Munich Malt
1 lbs Caramel/Crystal Malt - 40L
8.0 oz Chocolate Malt
6.0 oz Acid Malt
4.0 oz Midnight Wheat
I mashed with 5.75 gal of water at 164.9 F (153F mash temp) and sparged with 4.15gal of 180.0 F water.
1st runnings: 4gal, 1.074
2nd runnings: 4gal, 1.032
Pre-boil: 8gal, 1.054
Using Kaiser's efficiency brewsheets, I noticed that on this batch I got 91.6% conversion effiency (way higher than usual).
After everything was finished, I added 5 gal cold water to the mash tun, stirred and drained. From that, I got 1.020 wort. The spreadsheet says this is a 68% lauter efficiency.
Is that a normal lauter efficiency for batch sparging with a 10gal Igloo cooler?