Which? and the Food Standards Agency (FSA) have issued advice on foods that should be reconsidered before reheating in a microwave. While microwaving leftovers can be a convenient way to reduce food waste, some items may pose health risks or result in an undesirable texture.
Hard-boiled eggs are identified as a potential hazard, with intense microwave heat causing steam to build up and potentially leading to explosions. This can create a mess or even cause scalding injuries.
Other foods, such as pastry dishes, pizza, and chips, may suffer in quality. The rapid heat and steam from a microwave can compromise their texture, making pastry soft, pizza bases soggy, and chips limp. Thick cuts of meat like steak can also become tough and dry, and may heat unevenly.
Homemade frozen meals, particularly large or dense portions containing dairy or minced meat, risk uneven cooking from frozen. The FSA recommends defrosting these meals thoroughly in the fridge before reheating to prevent bacterial growth. Additionally, the FSA advises against reheating any food more than once, as repeated temperature changes can increase the chance of harmful bacteria developing.