Do You Have To Thaw Frozen Lasagna Before Reheating It?

Thick, heavy, layered with sheets of pasta and cheese, frozen lasagna is kind of comparable to a brick — something that will take hours upon hours to defrost. Maybe you've proudly meal-prepped a classic lasagna Bolognese or a more veggie-forward spinach and artichoke variation. The nights are getting cooler, your weekdays are busy, and it's time to take your creation out of the freezer and finally enjoy it.

But what's the best way to do that? Good news: It's up to you. Depending on your preferences, you can either thaw your frozen lasagna in the fridge first or stick it straight into the oven as-is. Thawing is a lengthy process, meaning you should allow the lasagna to defrost in your refrigerator overnight before reheating it at 375 degrees for about an hour. Cooking straight from frozen means an hour to even 90 minutes spent in the oven as the dense casserole heats all the way through.

While frozen lasagna might not seem like one of the great dangers of the world, it's still important to consider food safety when defrosting. According to the USDA, frozen perishable food should not be thawed at room temperature. In general, perishable food should not be left out for more than two hours in any setting between 40 and 140 degrees Fahrenheit, aka the "danger zone." After those two hours, bacteria can begin growing rapidly, making food poisoning a strong possibility.

Defrosting your lasagna in the fridge will allow it to thaw while keeping it under 40 degrees Fahrenheit. In other words, your food will still be safe to eat after sitting in the refrigerator overnight. And thawing it directly in the oven will keep its surrounding temperature well above 140 degrees, providing another safe option.

Whether you're using the thaw-in-fridge method or sticking your dinner right into the oven, be sure to spend the last 10 minutes of baking time with your lasagna uncovered. This will allow the top layer to develop a pleasant crispness — as though the lasagna was never frozen in the first place. Garnish with fresh parsley, basil, or even a squeeze of fresh lemon to further freshen your once-frozen dinner.