Milling Around

My first task as an apprentice was to mill some foisy wheat.  The concept is simple: pass whole grains through stone grinders to make flour.  Doing it well, however, can be tricky and requires much attention.

The East Tyrolean Mill

Our darling mill came from Austria.  Doesn't it look like a wooden toy?  I feel as though I'm in Giupetto's shop.  The machine looks arcane, but is actually powered by an electric motor.  The top right is the hopper where grain is stored.  The grains pour into the stone wheel compartment below at a rate that can be adjusted by widening or narrowing a board at the bottom of the hopper.  Once the grains pass through the stones, it becomes flour of varying sizes that pass through different sized sifters.  We set up the outputs so that flour comes out first, then confectioners' flour, bran, and whole bits out the back. The buckets collect the resulting flour and bran.

Top to bottom: Hopper, stone wheels, stone adjuster, sifter and stone switches

After the motor is turned on, I start up the sifters and the stones by rotating the grey switches in the bottom left of the photo. Then, I turn the stone adjuster wheel, that metal wheel, to separate the stone wheels.  The wheels need to be apart as not to wear away at each other when grain isn't present.  I slowly bring the wheels together until I hear them lightly rubbing and pull them away just a tad.

Grains fed from hopper to stone wheels

I release grain into the stone wheel area by turning a knob (seen in the previous photo) that adjusts the space between that flat, detachable base and the upper part of the hopper.  I can fine-tune the gap by adjusting the distance between the two strings that holds up the base.

Left to right: Bran, confectioner's flour, whole wheat flour

I feel the flour coming out to get a sense of the temperature and texture.  As discussed at the Grain Growers Gathering, flour should not be milled at more than 112 degrees F, otherwise the proteins and gluten will be destroyed.  My body temperature is around 98 degrees F, so I use that as a gauge.  If the flour feels warm on my hand, then I adjust either the flow rate of grains into the stone wheels or widen the distance between the stones.  If the flour is warm and fine, then it's likely the stones are too close.  If the flour is warm and coarse, then it's like that I'm feeding too much grain at once. 

Sound and touch are essential to proper milling.  One must listen for the sound of the stones to make sure they're not grinding too closely.  There's no other way to tell if you're milling correctly other than to feel the flour.  It's difficult to strike a balance between temperature and texture.  I want a fine grain, but not at the expense of losing the usefulness of the flour.

SeriousEats.com posted some articles that helped me understand the effects of different kinds of milling fineness. There's one of wheat flour classifications and another on rising flour.  Another useful site is The Biscuit Doctor (not as many pictures).