Cornstarch is practically pure starch and so a more efficient thickener than flour. Cornstarch is manufactured by soaking the whole maize grain, milling it coarsely to remove the germ and hull, and grinding, sieving, and centrifuging the remainder to separate the seed proteins. The resulting starch is washed, dried, and reground into a fine powder consisting of single granules or small aggregates. During this wet processing, the starch granules absorb odors and develop their own when their traces of lipids are oxidized, so cornstarch has a distinctive flavor unlike that of wheat flour, which is milled dry.