Instead of using pure cake flour, wheat flour or a mixture of wheat flour and raw wheat starch is used. The wheat flour is bleached to remove any brown pigments and produce a bright white color. The pH of the bleached flour is between 3 and 4.5, although the optimal pH of starch gelatinization is between 3.7 and 3.9. Acidifiers are used in order to reach this pH range. The optimal flour protein content is between 3% and 4%, and must be below 4.5%. If a mixture is used, at least 20% by weight should be wheat flour. A small amount of raw wheat starch may be added to the sugar as a grinding aid.