There isn't a specific limit on how many times you can reheat pizza slices in the microwave. However, each time you reheat pizza, the quality and texture of the pizza may deteriorate. The microwave's heating process can cause the crust to become soggy and the cheese to become rubbery.
If you want to reheat pizza in the microwave, here are some tips to help preserve the quality as much as possible:
Use a microwave-safe plate or dish: Ensure that the plate or dish you use is microwave-safe and can withstand the heat.
Reheat in short intervals: It's better to reheat the pizza in shorter intervals rather than all at once. Start with 30-second intervals and check the pizza's temperature and texture between each interval.
Cover the pizza: Placing a microwave-safe cover or a microwave-safe lid over the pizza can help retain moisture and prevent it from becoming too dry.
Use a lower power setting: If your microwave has adjustable power levels, use a lower setting, such as 50% power. This can help heat the pizza more evenly without overheating certain parts.
Consider using a microwave crisper tray or a pizza stone: These accessories can help to improve the crispness of the crust while reheating.
It's important to note that reheating pizza multiple times can increase the risk of bacterial growth, especially if the pizza has been left at room temperature for an extended period. If you have any doubts about the safety or quality of reheated pizza, it's better to err on the side of caution and discard it.