Do you need to grind flaked rye and malted rye before mashing? Didn't on my first all-grain and I'm not terribly pleased with the lack of extraction. Used the appropriate rests and extra amylase. Ran across a post that Denny did on another site that mentioned grinding malted rye. Is this always necessary?
You have to grind the malted rye to expose the endosperm for gelatinization and conversion. Flaked rye has already been gelatinized and can be added to the mash without any pre-processing.
The rye kernel is smaller than barley. I've found that it's best to tighten up your mill a bit to give a good crush.