Manipulating grain: Kilning and milling
In addition to these grains, you can also manipulate malted barley in a variety
of ways to create unique specialty malts. Kilning, or roasting the grain to various
degrees, is one way of achieving this variety. Depending on the degree of
roasting, specialty grains imbue beer with a broad palette of earth-toned
colors, and their flavor contributions range from caramelly to chocolatey to
roasty to smoky. Milling is the process of cracking the grain husk to allow
access to the natural sugars contained within the kernel (also called
cracking).
Don’t mill highly kilned grains such as roasted barley and black malt.
Because they’re quite brittle, they have a tendency to crumble during the
milling process, creating a fine, dark grain powder that adds harshness to
your beer.
Homebrew recipes usually call out specialty grains by the pound or in increments
of a pound. In the absence of a kitchen or postal scale, you can measure
specialty grains with relative accuracy by using a measuring cup.
For conversion purposes, 1 cup of milled grain equals approximately 1⁄4 pound,
ergo, 4 cups equal 1 pound.