A system for applying microwave energy to a product and having a first microwave oven, a relaxation tunnel connected to the first microwave oven, and a second microwave oven connected to the relaxation tunnel. The microwave ovens may have a cross-sectional area that is at least twice the size of the cross-sectional area of the relaxation tunnel. Generally, no microwave energy is applied to the product while travelling through the relaxation tunnel. Preferably, the product spends at least twice as much time within the relaxation tunnel as the first or second microwave ovens. The microwave ovens preferably apply the microwave energy directly to the product.