Why are most crisp cookies low in moisture after baking?

Most crisp cookies are low in moisture after baking—typically containing less than 5 percent water—because this low moisture level is essential for achieving their characteristic crisp texture and ensuring good storage stability.1

During the baking process, the texture of a cookie is heavily influenced by the sugar used in the dough. There is a competition for the limited water content between the slowly dissolving sugar and the gluten of the flour. By limiting the available water, the sugar helps control the spread and expansion of the cookie, ultimately resulting in a dry, crisp final product.1