Some ol' Air Force buddies are gathering in Omaha, NE for a reunion and one sent me this
"After the boil, the
hot wort (the beer before it's really beer) is fired through a hop
back, a unique four-barrel stainless steel tank filled with a gratuitous
amount of raw flower Amarillo, Centennial, and Cascade hops, extracting
the aromatic oils and flavor of the hops."
Cheers and thanks to Don Baker for thinking of me!