Although they brew twice a day, they still mash by hand. Computers may be used to track mash temperatures, but this still remains mostly a manual operation. The wort runs to the two coppers for a 1.5-hour boil. After the boil, the hops are removed via a screw compressor separator. Then the wort is further cleared of trub via a whirlpool, then runs to open squares, where the yeast is pitched.
All fermentation begins in open square fermenters, although they are shallower than most.
The initial temperature in the squares is kept quite low, around 60F, because they don't contain attemperating coils. The remainder completes its fermentation in open or closed squares and is used for some of the standard Marston's house beers as well as for blending. The premium Pedigree is a 50-50 blend. All the beers are appropriately labeled if they were made with a portion from the union sets. The beer in the unions remains in the system for 4.5 days at around 62F. To maintain the proper fermentation temperature, water is pumped through attemperating coils in the casks.