Set aside the next portion early
If you know part of dinner is for another day, prepare clean storage containers before serving. That makes it easier to portion the food promptly instead of leaving a large pot on the stove through the evening. Label the portion with its contents and cooking date.
Use shallow containers for a large quantity rather than storing the entire deep pot. USDA guidance allows hot food to go directly into the refrigerator and recommends dividing large amounts for faster cooling. Waiting for a big pot to feel completely cold on the counter creates avoidable risk.
Use the clock rather than the smell
Refrigerate perishable leftovers within two hours, or within one hour above 90 F. Keep the refrigerator at 40 F or below. USDA recommends using refrigerated leftovers within three to four days or freezing them. Follow any shorter guidance for a particular food.
A pleasant smell cannot establish that an old container is safe. Keep the date on food when it moves into another dish; turning yesterday's chicken into today's soup does not erase its storage history. If safe time or temperature is uncertain, do not taste it to find out.
Warm only the amount you need
Portioning before storage can reduce repeated warming and cooling. Take out the amount for the next meal and leave the rest chilled. Add a suitable splash of liquid to soups or sauced dishes when reheating, then check the food rather than relying on steam above the pot.
Reheat leftovers to 165 F. Stir and check more than one spot in a microwave-heated portion because heating can be uneven. Use microwave-safe containers and the appliance's directions for covering and standing time.
Make the refrigerator readable
Put the next day's lunch where you can see it, with its label facing forward. A small section for food to use soon can help, provided it does not block airflow or let raw food drip onto ready-to-eat portions. Check the oldest dates before starting another large batch.
Freeze portions you will not use within the recommended time while they are still in good condition. Include the date and a reheating note on the label. A portion called beans is less useful than one that also tells you whether it includes broth and how much it serves.
Keep in mind
Reheating cannot reliably undo unsafe storage or remove every toxin that may have formed.
A refrigerator thermometer checks the appliance; a food thermometer checks the reheated meal.
