I have Brewed 20 + batches of all grain. Every once in a while I come up with a very low gravity but I didn’t do anything different. I crush my grain at the brew store. I noticed that the grain is crushed but the grain hulls are not broken open. I rubbed the grain with my hands and broke open the hulls. On that batch my gravity went way up. Just a fluke? does any body else have this problem. If the grain is crushed in the hull, but the hull is still intact, does that equal zero gravity?
No, but as you noted, the degree of the crush is a major factor. Read more:
http://braukaiser.com/wiki/index.php?title=CrushEvalIf crushing at the store I would run it through the mill twice. Or bring it home and roll it with a rolling pin. Or get your own mill :cheers:
Its actually good if a lot of the hulls are intact, they form a better filter bed that way. You get more of that if you spritz the malt with water a few minutes before crushing.
You just want to be sure the malt is cracked into small pieces with some flour. A real coarse crush will affect conversion. You can compensate by mashing longer and stirring periodically, but theres a limit to that.
