Cooking styles vary, but the outcome is the same — wholesome baked beans in a thick sauce, seasoned to taste. Whether the beans bake in a rich, brown sugar sauce or tangy tomato base, the chance of leftovers is slim to none. If there happen to be a few morsels left at the bottom of the casserole dish, though, refrigerate what remains. Left out overnight, baked beans are not safe to eat the next day.
Refrigerate any leftover baked beans within two hours of cooking. Bacteria will grow at temperatures between 40 and 140 degrees Fahrenheit and can reach dangerous levels after two hours. If the air temperature is 90 F or higher, refrigerate baked beans within one hour. Throw away a baked bean casserole left out longer than two hours.
In the Fridge
To store leftover baked beans safely, scoop them into an airtight container and refrigerate at 40 F or below; the baked beans keep for up to four days. Within the four days, it is important to either eat the beans or transfer them to the freezer. Refrigeration does not kill bacteria, but it does slow its growth.
Reheat leftover — and safely stored — beans over low heat on the stove top. Stir constantly to prevent scorching, adding small amounts of water to the sauce if the consistency is thicker than you prefer. Remove the beans from the heat once the sauce begins to bubble.
The Freezer Option
If you do not plan to eat the baked beans within four days, pop them in the freezer. The cold temperatures in the freezer stop bacterial growth, keeping them safe to eat indefinitely, although quality begins to diminish after a month or two. Thaw frozen baked beans in the refrigerator before reheating.
References and ResourcesCenter for Science in the Public Interest: Rules for Leftovers: 2 Hours -- 2 Inches -- 4 Days
Central Bean Company Inc.: Cooking Beans
StillTasty: Beans, Baked, in Sauce (Including Molasses, Brown Sugar, Tomato), Commercially Canned or Bottled -- Opened