Why do foods not brown in the microwave?

Foods do not brown in the microwave primarily because there is no direct heat source involved in the cooking process. Microwaves cook food by emitting energy that causes water molecules within the food to vibrate, generating heat through this process. This method is quite different from conventional cooking, which often involves direct contact with heat sources, such as stovetops or ovens, that can create a Maillard reaction or caramelization—processes responsible for browning.

The absence of dry heat means that while food is heated and cooked, it does not undergo the same chemical changes that typically lead to browning. This is why even though food may be cooked through and heated sufficiently, it does not develop that appealing brown color commonly seen in baked or pan-fried dishes.