A slower turn
Our Austrian Osttiroler mill brings grain between natural granite stones turning at approximately 180 RPM. The furrows guide kernels outward as the stones shear and grind. We aim to keep the flour and its germ oils below 92°F through careful milling and attention to conditions; temperature varies with the grain, feed rate and mill settings.
What stays in the flour?
A wheat kernel contains starchy endosperm, an oil-rich germ and outer layers of bran and aleurone. Whole-grain stone milling brings these parts together in the flour. The germ and outer layers contribute flavor, carotenoid pigments, enzymes and minerals. Heat and storage still affect their condition, so cool handling and fresh flour matter.
Conventional roller milling separates grain into streams, often removing much of the bran and germ from refined white flour. Stone milling and roller milling both allow different levels of separation; what reaches the bag depends on the miller’s choices.
Extraction, explained
Extraction is the proportion of cleaned grain retained as flour. An 85% extraction means approximately 85 parts flour from 100 parts grain by weight, with some coarser material sifted away. Whole-grain flour retains the grain’s constituent parts. Extraction is a useful guide, but it doesn’t tell you every detail of a flour’s performance.
Freshly milled flour can absorb water differently from one batch to the next. Start with the baker’s calculator, then make small adjustments as the dough comes together.