Those corona style mills always looked to me like they can't be accurately set,like the grain mills usually used in home brewing. I popped the $130 on the Barley Crusher grain mill with the crank handle,wood base made to fit a 5 gallon bucket & 7lb hopper. It has notches on the adjustment knobs for the factory setting of .039". I've found that to work very well indeed with PB/PM BIAB brewing with a single pass. Good crush for biab brewing,& a lot less of that poofy flour stuff that really isn't needed. I put a round cake cooling rack in the bottom of my 5G SS BK/MT,then stretch the nylon paint strainer bag over the lip of the kettle & hang my floating thermometer in the kettle with a hangman's noose made out of a few breadbag twisties tied to the kettle handle. Makes for easy depth adjustment as well.
This way,I can mash 5-6 pounds of grain in 2G of water quite easilly. Then heat sparge water of 1.5-1.75 gallons while the BK/MT is wrapped up in my quilted winter hunting coat for the mash. The sparge water heats up in a 2G SS stock pot. I lift the grain bag out of the kettle & into a SS colander on top of the BK/MT to drain. Then sanitize a 2C Pyrex measure to slowly pour the 165-168F sparge water over the open grain bag to sparge off more sweet wort goodness. I much prefer this method to get my total boil volume of 3.5-3.75 gallons in my 5G (20QT) SS kettle. My efficiency went through the roof on my last batch. I brewed two batches of pm IPA's,same recipe save for the hops used. First batch came out with an OG1.061. Wow,cool...I'll take that. Then the second batch a couple days later came out OG1.074. Same amounts of everything,same process,stirred top off roughly & for the same few minutes straight as well. I measured the grains in half from the total amount purchased at 5.6lbs. The second batch,I didn't bother,since all were halved the first time. That is to say,the 1pound bags that were to be used a half pound at a time. There were 1 lb bags labekled for what type they were,& I measured those out of curiosity alone. They were indeed over very slightly weight-wise,but only about one tenth pound. Very good efficiency above the norm is indeed possible with biab.
