What happens if doughnut dough is overmixed?

When doughnut dough is overmixed, it develops too much gluten. Gluten is a protein formed when flour is mixed with water and kneaded. In the context of doughnuts, which ideally should have a tender and slightly soft texture, overdevelopment of gluten results in a denser, chewier product. This undesirable texture can compromise the lightness and fluffiness that are characteristic of a good doughnut.

In contrast, the other options do not accurately describe the effects of overmixing doughnut dough. For example, while sweetness is related to the ingredients used rather than the mixing process, uneven frying results from factors such as dough density and moisture levels, not directly from overmixing. Similarly, a hard crust is more associated with baking temperatures or times than with the mixing of the dough itself. Hence, the primary concern with overmixing doughnut dough revolves around the inappropriate development of gluten.