How to assemble a grain roller mill for a microbrewery/brewpub

While a commercial mill such as the Apollo Mills Sven Mill is a real workhorse, this mill setup can work well for budget concious startup brewpubs. It balances functionality and performance with price. The Crankandstein 328G roller mill will crush approx 15lb/minute and produce a nice crush that balances grain bed fluidity with mash efficiency. 

Note: we have recently assembled a grain mill using one of our Heavy Duty Utility Carts (image to the right). Building it on the utility cart means that it is fully portable and can be moved where and when needed. Its' construction is very similar to what was discussed in the video above. The main differences are that the vent boot had to be cut to fit through one of the cart top support ribs, we used an electric motor that had a built in 10:1 reducer, and instead of a power switch, we used a L5-15 plug on the motor cord so it can be plugged into the BREWHA Brewery Power Controller (1.5BBL and larger) pump switch and toggled with that. And instead of placing the grain bag underneath the table as is shown in the video, the grain bag sits to the side of the cart, and the vent boot is at 45 degrees to point out to the bag; a short vent extension can be used to bring it out further if desired.

Items used in the build

• Heavy duty wooden table (used)—$40
• Two 7' pieces of 1.5" angle iron and eight bolts/nuts/washers—$30
• Crankandstein 328G 8" fully geared three roller mill—$400
• Crankandstein wooden mill plates and bolts (top and bottom)—$30
• 1hp 120V fully enclosed, fan-cooled Electric Motor (1675rpm)—$160
• Flex couplers for motor and speed reducer, and spider—$30
• 10:1 Horizontal Shaft Worm Drive Speed Reducer and oil—$110
• Bolts for motor, speed reducer and mill—$10
• Electrical box, switch, cord grips, connectors and wood motor mount—$25
• Flashing and universal vent boot—$17
• Monster hopper and extension (MMH-3Pro; MMH-EXT)—$60

Option 1 (direct drive; this works the best in my experience):

• Flex couplers for speed reducer and mill drive shaft, and spider—$30
• Board to raise mill shaft to same height as speed reducer shaft—$5
• Positive: best milling action and won't slip
• Negative: there is less protection against damage if the mill jams (e.g. from a tool falling in while operational); can put a screen over the hopper opening to limit the risk

Option 2 (belt drive):

• Split bushing and sheave for speed reducer —$16
• V Belt—$5
• Pulley for mill drive—$10
• Six brackets and ten bolts for tensioner—$40
• Benefit: safer as the belt 
• Positive: safer
• Negative: since grain is hard, it can jam the rollers somewhat easily causing the belt to slip; can be very frustrating

Tools used in build:

• Drill and drill bits
• Wrenches
• Jig saw
• Tape measure, square and pencil

Controlling vorlauf and lauter rates for best efficiency and preventing a stuck mash

Good crush size for high bed fluidity and mash efficiency