A dry grind ethanol production process and system with front end milling method is provided for improving alcohol and/or by-product yields, such as oil and/or protein yields. In one example, the process includes grinding corn kernels into particles then mixing the corn particles with a liquid to produce a slurry including oil, protein, starch, fiber, germ, and grit. Thereafter, the slurry is subjected to a front end milling method, which includes separating the slurry into a solids portion, including fiber, grit, and germ, and a liquid portion, including oil, protein, and starch, then milling the separated solids portion to reduce the size of the germ and grit and release bound starch, oil, and protein from the solids portion. The starch is converted to sugar, and alcohol is produced therefrom then recovered. Also, the fiber can be separated and recovered. Oil and protein may be separated and recovered as well.