Fridge:Let the pinto beans cool completely (mashed or not), and place in airtight containers. Store them in the refrigerator for up to 3 days.
Freezer:You can also freeze pinto beans in freezer Ziploc bags and lay them flat to save space, or freeze for up to 3 months in small portions.
Reheat:If your pinto beans are frozen, then you will need to thaw them in the fridge overnight. Reheat over the stovetop or in the microwave, and you’ll probably need to add a splash of water as the beans will be thickened when they’re cold.