According to the USDA—those brave government scientists who also tell us not to eat raw cookie dough—cooked lasagna lasts three to four days in the fridge. After that, it’s a science experiment, not dinner. Day four is like the last episode of a good show: still enjoyable, but you know the credits are coming.
I once kept a tray for six days and convinced myself the green fuzz was “herbs.” It wasn’t. Surprising fact: your fridge is actually a time machine, but it only slows down spoilage; it doesn’t stop it. So mark your calendar with a cheese emoji, or just use a real marker on the container.
