Freeze cooked beans in their cooking liquid, but freeze cooked grains drained. For both, the first rule is to cool them quickly; do not leave hot food sitting on the counter. Divide the food into portions and freeze it in flat bags so it freezes quickly and you can take out only what you need. Use rice and pasta without thawing them first, reheating them with steam until they reach 74°C / 165°F throughout.
The two foods are stored in the same freezer but packed differently. Beans are frozen in their cooking liquid because they shrink and toughen when they dry out; the liquid protects them from the freezer’s dry air. Rice, bulgur, and pasta have already absorbed their water; adding more liquid makes them mushy. So grains are packed after draining and cooling. This distinction is made during packing and cannot be corrected later. That is why, even if the 2 foods are frozen on the same day, they need 2 separate preparations.
The first rule for both is to cool the food quickly. Do not put hot food directly in the freezer; it raises the temperature inside and stays for a long time in a range that is favorable to bacteria as it cools slowly. Transfer it to a wide container and spread it in a thin layer. This step is even more important for rice and pasta because cooked rice can become problematic quickly at room temperature. Placing the container in ice water cools the food even faster and significantly shortens the cooling time.
Portioning makes things easier. Put meal-sized amounts in separate bags or small containers, remove the air, and seal them tightly. If the bags are filled flat and frozen on a level tray, they freeze quickly and stack like files in the freezer. Label each one with the food and date. A large frozen block of food has to be thawed completely every time. If you choose glass containers, use ones made for freezer use; ordinary glass can crack in the cold. Do not fill containers to the brim, either, because the contents expand somewhat as they freeze.
The reheating method depends on the food. Put beans in a pot, add some water, and heat them over low heat, stirring. Reheat rice and pasta without thawing; sprinkle a few spoonfuls of water over them, cover the container, and let the steam heat them. In both cases, heat the food until it is steaming throughout; lukewarm is not enough. Stir rice reheated in the microwave occasionally, or some spots may stay cold.
There are a few limits. Do not refreeze food that has thawed. Finish a reheated portion at that meal; do not cool and store any leftovers again. Dishes thickened with starch release water when frozen, so thicken them during reheating. Beans and grains keep good quality in the freezer for about three months; after that, their flavor and texture decline. Check the dates on the bags regularly and move older ones to the front. Avoid opening the freezer door unnecessarily, since temperature fluctuations cause ice to form on the food.