But how is DFH doing it? I have an ignorance of professional brewing techniques. Certainly they aren't batch-sparging but pumping the mash around etc... Drain the and fill the mashtun and kettle consecutively since the mash takes about as long as the boil should.
I don't know all the specifics for sure, but they have 4 giant hot liquor tanks ~200 barrels each. I presume these are holding water at different temperatures. I think they have a mash/lauter tun, kettle and whirlpool. And enough stainless steel piping for your best girl to do her makeup. Plenty of computer control helps keep the batches flowing through the system I'm sure. I don't know how often they turn out a batch.