Researchers at Cornell University determined that foods can explode or cook unevenly in a microwave as a result of their shape, pore size and other factors. They found that in a microwave, round foods tend to cook at the center first while frozen foods will not thaw at an even rate. Foods with high density, such as tofu, do not allow steam to escape from the heating center and are at higher risk for an explosion.
Tofu is one of the most common preparations of soy. The soybean-derived protein product is somewhat gelatinous, so microwaving is usually not the best choice for its preparation as it will not firm the product. Tofu can be thawed in a microwave for a short time. Most tofu recipes recommend frying, grilling or baking the product, rather than microwaving it. Microwave preparation does not allow a chef to brown and firm tofu when such a technique is desired. It may heat tofu inconsistently and under certain conditions could cause it to explode.
Many popular soy products that mimic meat, such as tofu "turkeys" and burgers, can safely be microwaved. In fact, microwave preparation instructions are often available on the packaging but are usually not the recommended method of preparation. Some soy products may be packaged in containers that are unsafe for microwaving due to lack of ventilation, type of material or other reasons. Soy products that are particularly round, have inconsistent textures or are quite dense may carry a higher risk for explosion when microwaved.
Select tofu that is firm to the touch for best cooking results. Steam it to rid it of bacteria, if necessary, and grill or fry it in a pan with oil. When microwaving soy or tofu, always do so in short intervals and turn it frequently for even cooking. For best thawing results, allow tofu to warm to room temperature rather than microwaving. Avoid microwaving dense masses of tofu or other soy foods, as these are apt to cook unevenly and possibly explode.