Reheating homemade queso requires two steps: defrosting and reheating. Begin defrosting your dip by placing it in the refrigerator for about 24 hours, or placing dip in a microwave-safe dish and heating it for 30 seconds at a time until it’s just thawed. Defrosted queso may appear separated or lumpy, but properly heating and stirring should recombine ingredients. Once it’s thawed, pour the dip into a pan and reheat it on a low heat setting on your stove top, stirring continuously. Remove queso from the heat once it starts to simmer and serve it immediately.