9 c. whole wheat flour
8 c. white flour
4 tsp. salt
1 c. instant nonfat dry milk
1 c. packed brown sugar or 1 c. white sugar

Combine first 4 ingredients. Stir with wire whisk. Press brown sugar through coarse sieve. Stir into flour mixture. Pour into 18 cup container with tight fitting lid. Store in refrigerator 10-12 weeks or 6 months in freezer.