How Long Can Gravy Sit Out?

The 2-hour rule, the hidden threat of Clostridium perfringens, and how to safely cool and reheat gravy.

We have already covered how long chicken, pizza, and mayonnaise can safely stay out on the counter. Today we are looking at a holiday favourite and a comfort food classic: gravy.

Why gravy is a hazardous food

Under Ontario food safety laws, potentially hazardous foods are those that provide an environment where dangerous bacteria can survive, grow, and multiply. To multiply quickly, bacteria need two main things: moisture and protein. Gravy is essentially a mixture of water or broth, which is high in moisture, and meat drippings, which are high in protein, thickened with starches like flour or cornstarch. Because it is packed with moisture, protein, and neutral starches, gravy is essentially an all-you-can-eat buffet for harmful microscopic bacteria.

The 2-hour rule: how long can gravy sit out?

Because gravy is a potentially hazardous food mixture, the strict legal and scientific limit for how long it can sit out at room temperature is 2 hours.

Why only two hours? This rule exists because of the Temperature Danger Zone, the temperature range between 4°C and 60°C (40°F and 140°F). When a warm bowl of gravy sits on your dining room table, it falls squarely within this zone. In this warm environment, bacteria wake up and multiply incredibly fast. If the temperature is close to normal human body temperature, 37°C (98°F), bacterial cells can divide and double their numbers every 10 to 20 minutes.

If your gravy has been sitting out at room temperature for more than two hours, it has violated government food safety laws and is no longer safe to eat. You cannot put it in the fridge to save it, and you cannot just microwave it to kill the germs. After two hours, it must be thrown in the garbage immediately.

The hidden threat: Clostridium perfringens

You might be wondering, but I boiled the gravy on the stove; doesn't boiling kill all the bacteria? Unfortunately, no. Gravy is considered exceptionally dangerous when left out too long because of a specific type of bacteria called Clostridium perfringens.

Clostridium perfringens is a pathogenic bacterium found naturally in the environment and in the intestines of animals. It is highly associated with high-protein and starch-like foods, making gravies and meat stews its absolute favourite places to grow. What makes this bacterium so incredibly dangerous is its ability to form spores.

When bacteria are exposed to the extreme heat of boiling gravy on the stove, they protect themselves by forming a hard spore. These spores act like an invisible shield, allowing them to easily survive the cooking process.

When you take the gravy off the stove and let it sit on the table, it begins to cool down into the Temperature Danger Zone. The surviving spores sense that the temperature is comfortable again, and they wake up, turning back into active, growing bacteria. As they multiply in your warm gravy, they can produce dangerous toxins. If a person eats this temperature-abused gravy, they will likely experience severe abdominal pain, stomach cramps, and diarrhea within 8 to 24 hours.

Because Clostridium perfringens is a heat-resistant, spore-forming bacteria, simply reheating the gravy later will not destroy the toxins that have already been created. Keeping your gravy out of the Danger Zone is your only true defence.

How commercial buffets keep gravy safe (hot holding)

If gravy can only sit out for two hours, how do restaurants, buffets, and cafeterias safely serve warm gravy all day long? They do this by using a food safety method called hot holding.

If a restaurant wants to keep gravy out for customers, they cannot just leave it in a bowl on a counter. They must place the gravy in a specialized piece of equipment, such as a steam table or a soup urn, and set it to high. According to the Ontario Food Premises Regulation, any hazardous food held hot for service must be maintained at a minimum internal temperature of 60°C (140°F) or higher at all times. At 60°C or higher, the food is safely above the Danger Zone, meaning bacteria cannot grow. Food workers must frequently use a sanitized probe thermometer to check the gravy and prove it has not dropped below this critical 60°C limit.

How to cool gravy safely

Improper cooling of hot foods is one of the leading causes of foodborne illness in Canada.

If you have leftover gravy you want to save for tomorrow, you must cool it rapidly. You should never take a massive, deep pot of hot gravy and put it straight into the refrigerator. A large pot will take far too long to chill, and the center of the gravy will stay warm and trapped in the Danger Zone for many hours.

Instead, the government mandates a strict two-stage cooling rule:

• Stage one. The gravy must drop from 60°C (140°F) down to 20°C (68°F) within two hours.
• Stage two. It must then drop from 20°C to a safe fridge temperature of 4°C (40°F) or lower within the next four hours.

To achieve this fast cooling, pour your hot gravy from the cooking pot into shallow metal pans no deeper than 2 inches. Metal conducts cold much better than plastic. Leave the pans partially uncovered on the top shelf of the fridge so the heat can escape, and stir the gravy frequently to speed up the chilling process. Once it hits 4°C (40°F), you can cover it tightly.

How to reheat gravy safely

When it is time to enjoy your leftover gravy, you must be very careful. Reheating food means you are forcing it to pass back up through the Temperature Danger Zone.

Because it contains meat products and moisture, leftover gravy must be rapidly reheated to a minimum internal temperature of 74°C (165°F) and held at that temperature for at least 15 seconds. The government training manuals state that liquids such as soups, stews, and gravies should be brought to a full, rolling boil to ensure they are safe.

You must use a stove or a microwave to reheat your gravy. You can never use a hot-holding unit, like a steam table or warming tray, to reheat food because those machines heat up too slowly and leave your gravy in the Danger Zone for too long.

Finally, remember the golden rule of leftovers: never use the leftovers of a leftover. Because leftover food passes through the Danger Zone multiple times, during cooking, cooling, and reheating, it becomes riskier each time. If you reheat a batch of gravy and do not finish it, throw the rest away.

Final food safety quiz

Test your memory with these 5 questions, then tap to reveal the answer.

For the full guide to safe holding times for every food type, see the main how long can food sit out guide.