Exposure to anhydrous ammonia has been suggested as a pretreatment for corn milling. Batches of corn were exposed to ammonia under controlled conditions. The amounts of ammonia absorbed and reacted with the corn were measured. The amounts were not more than are needed as nutritional supplement for yeast fermentation to ethanol. Loosening of the hull was observed qualitatively, and subsequent shearing in a disk mill followed by steeping for 2,4,6, or 8 h showed that germ could be recovered at higher yield and after a shorter steeping time compared to untreated control batches. Quality of oil was not affected by treatment with ammonia.