The effect of hydration level on processing properties and the effects of hydration level, concentration of buckwheat bran flour and drying temperature on the physical and cooking quality of spaghetti were determined. Specific mechanical energy transferred to the dough during extrusion decreased 69% for semolina and 79% for semolina containing 30%, w/w, buckwheat bran flour, as hydration level increased 29-32% absorption. Little or no postdrier checking occurred in spaghetti made from semolina or spaghetti containing buckwheat bran flour when dried at high (70degreesC) or ultrahigh temperature (90degreesC). When dried at low temperature (40degreesC), tolerance to postdrier checking of spaghetti decreased as buck-wheat bran flour increased 0-30% (w/w). Hydration level before extrusion did not affect cooking loss of spaghetti made from semolina. However, cooking loss was greater from spaghetti made with semolina-buckwheat bran flour that was hydrated to 32% compared with 29-31% absorption. Cooked firmness of spaghetti containing buckwheat bran flour decreased from 0.588-0.471 Nm as hydration increased from 29-32% absorption. Cooking loss was lower and cooked firmness was greater when spaghetti containing buckwheat bran flour was dried at ultrahigh than at low temperature.