The Key Ingredient For Creamy Leftover Mashed Potatoes

We've all been there — the day after a large dinner party, there's a Tupperware container full of creamy, rich mashed potatoes that beckons us in the odd hours of the evening. So we do what anyone does with leftovers, reheat them in the microwave, perhaps even add a few sprinkles of cheese, and some scoops of coagulated gravy. But what comes out of the microwave is not what we had the night before; it's a sad mound of dry granules, with an odd lumpy sauce for gravy. So what went wrong?

Well, Southern Living notes that starchy dishes like mashed potatoes and baked casseroles tend to dry out quickly in the high-heat environment of the microwave. Thus, something as starchy as mashed potatoes requires a low and slow reheating to maintain that smooth texture. But with something as low stakes as leftovers, who really wants to take out an extra pan and stand over the pot, stirring constantly? If you're determined to use electromagnetic waves to heat your mashed potatoes, do yourself a favor and add one ingredient to quench those starches.

That's right, it's time to add even more of these luxurious fats to your mashed potatoes. Recipe developer JeanMarie Brownson suggests that you add milk or cream, or any dairy products to avoid drying up your old mashed potatoes (via Martha Stewart). Why milk or cream rather than plain water? Well, Science of Cooking explains the importance of adding dairy products to potatoes: The starches in a potato react differently to proteins in milk versus water. While water makes the potato starches swell and become gluey, casein in milk limits the swelling and creates a smoother finish.

This reaction is important to keep in mind when you're making your mashed potatoes and when you're reheating them the day after. If you're willing to reheat your mashed potatoes on the stovetop, a splash of milk or cream will still help you revive the creaminess of the potatoes from the day before, per Martha Stewart. However, if you want a quick and easy zap in the microwave, make sure to add lots of milk and cream. Heating your leftover potatoes in small increments of time and stirring in between will also help you since microwaves are famous for heating dishes unevenly, per Comsol. When you're happily digging into a warm bowl of creamy leftover mashed potatoes instead of a pile of dry, crumbly spuds, you'll be glad you put in the extra effort!