The FDA does not set a specific limit on how many times you can reheat food. There is no rule saying “reheat only once” or “reheat up to three times.” What matters, according to federal food safety guidelines, is whether the food reaches 165°F every time you reheat it, and whether it was cooled and stored properly between each cycle. In practice, though, each reheat cycle introduces risk, and most food safety experts recommend reheating only what you plan to eat in one sitting.
What the Guidelines Actually Say
The USDA’s Food Safety and Inspection Service, which works alongside the FDA on food safety, focuses on two things: temperature and time. When reheating leftovers, the food must reach an internal temperature of 165°F, confirmed with a food thermometer. Sauces, soups, and gravies should be brought to a rolling boil. There is no mention of a maximum number of reheats.
The reason there’s no hard number is that the safety calculation depends on how the food was handled each time. If you reheated a pot of chili, held it at a safe temperature, cooled it properly, and refrigerated it promptly, it’s in better shape than food that sat on the counter for an hour before going back in the fridge. The number of reheats is less important than whether you followed safe handling at every step.
Why Each Reheat Cycle Adds Risk
Bacteria grow rapidly between 40°F and 140°F, a range food safety professionals call the “danger zone.” Every time food passes through this range (warming up from the fridge, cooling back down after reheating), bacteria have a window to multiply. The more cycles, the more windows.
Reheating to 165°F kills most active bacteria, but it does not destroy everything. Some organisms, like Bacillus cereus (common on rice and pasta), form heat-resistant spores that survive normal cooking temperatures. If those spores germinate during a slow cooling period, the bacteria can multiply and produce toxins. The emetic toxin produced by Bacillus cereus is heat-stable, meaning reheating the food again will not break it down. No amount of microwaving will make that food safe.
This is why the cooling step matters as much as the reheating step. The FDA Food Code requires a two-stage cooling process for cooked foods: from 135°F down to 70°F within two hours, then from 70°F down to 41°F or below within the next four hours. At home, you can speed this up by dividing large portions into shallow containers before refrigerating.
The Practical Answer: Reheat Only What You’ll Eat
Rather than reheating an entire batch of leftovers and putting the rest back in the fridge, portion out only what you need. This keeps the rest of the food undisturbed at a safe refrigerator temperature and avoids unnecessary trips through the danger zone. A large container of soup that gets reheated, partially eaten, cooled, refrigerated, and reheated again has spent far more cumulative time in the danger zone than a portion that was scooped out and heated once.
If you know you won’t finish leftovers within three to four days, freeze them. Frozen leftovers follow the same reheating rule: they must reach 165°F internally. When thawing leftovers in a microwave, continue heating until they hit that temperature rather than stopping once they’re thawed.
Rice and Pasta Need Extra Caution
Rice deserves special attention. Roughly 95% of emetic illness cases linked to Bacillus cereus involve rice. The spores are present on raw rice from the soil where it was grown, and they survive boiling. If cooked rice sits at room temperature while the spores germinate and bacteria multiply, toxins accumulate that no amount of reheating will destroy. The same risk applies to pasta and noodles.
The fix is simple: refrigerate cooked rice within one hour if the room is warm (above 90°F), or within two hours otherwise. Store it below 41°F. When you reheat it, get it to 165°F throughout. If rice has been left out for several hours, especially in a warm kitchen, discard it. Reheating it won’t help.
How to Reheat Safely in a Microwave
Microwaves heat unevenly, which can leave cold pockets where bacteria survive. To reheat safely, cover the dish with a lid or microwave-safe wrap, leaving a corner or vent open for steam to escape. Stir or rotate the food at least once midway through heating, even if your microwave has a turntable. After removing the food, let it stand for at least three minutes. The standing time isn’t optional: cooking continues during this period, and it helps equalize the temperature throughout the food. Then check with a thermometer to confirm you’ve hit 165°F.
What Happens to Food Quality
Even when food remains safe, repeated reheating takes a toll on nutrition and texture. Research published in Food Science & Nutrition found that each round of reheating significantly reduced the protein, mineral, and fiber content of meat. Calcium, iron, magnesium, phosphorus, sodium, and potassium all decreased with additional heat exposure, regardless of whether the food was boiled, roasted, microwaved, or fried.
The fat in reheated food also degrades. Peroxide values, a marker of fat oxidation, increased with each reheating cycle. This oxidation is what gives reheated meat that stale, “warmed over” flavor. Proteins break down through browning reactions, and the texture changes as the food’s ability to hold moisture shifts. Frying added the most fat (from absorbed oil), while boiling and microwaving caused the greatest protein losses over time. None of this makes the food dangerous on its own, but it does mean that by the third or fourth reheat, you’re eating something nutritionally diminished and noticeably less appealing.
The bottom line is straightforward: there is no FDA-mandated number of safe reheats. The real rules are to hit 165°F every time, cool leftovers quickly, refrigerate within two hours, and avoid letting food linger in the danger zone. The easiest way to follow all of those rules is to reheat only the portion you plan to eat.