How Long Can You Actually Leave Coleslaw Out?

At some point, most of us have heard that you can't leave mayonnaise-based dishes like potato salad and coleslaw out for too long, especially outside in the heat. And that's true, perishable food does need to be refrigerated. However, it's actually not the mayo that makes coleslaw exceptionally susceptible to spoilage at warmer temperatures — it's the cabbage.

In the realm of food safety, most vegetables (cabbage included) are known as low-acid foods. This basically means that there's not enough acid in that particular food to stave off bacterial growth. Foods that contain a lot of water, like cabbage, are typically even more dangerous. This is because when produce is cut and the juices are able to drain out, bacteria see that liquid as a green light to set up shop. The more cut surface area a food item has, the more moist nooks and crannies there are for bacteria to thrive in. So when looking at a cookout staple like coleslaw, where the cabbage is shredded, there's plenty of opportunity for bacterial growth.

What's In Coleslaw?

Coleslaw, sometimes known simply as "slaw," is a type of chilled salad traditionally made from shredded cabbage tossed with a sweet and tangy mayonnaise-based dressing. Ingredients can vary between different coleslaw recipes, but you'll often find other vegetables like shredded carrots or even sliced onions or scallions added in. Like the cabbage, these veggie add-ins can also become breeding grounds for bacteria when left unrefrigerated. Coleslaw dressing often includes vinegar that acidulates the mixture, making it a less hospitable environment for those pesky bacteria. But unfortunately, it's not enough to halt bacterial growth completely.

How Long Can Coleslaw Sit Out?

The USDA, the government agency that oversees food safety rules, says that prepared foods like coleslaw can be left out at room temperature for up to two hours. After two hours, harmful bacteria can start to grow. Even if the coleslaw was stored in the refrigerator prior to serving, it could quickly dip into what food safety rules call the "Danger Zone" after being set out. The danger zone is between 40 and 140 degrees Fahrenheit; this is the range of temperatures where bacteria thrive.

The thing is, the two-hour rule is primarily a guideline. Other factors affect how long coleslaw can safely be left out. While it's best to keep any perishable food refrigerated at all times, there are many situations where that just doesn't make sense. Take, for example, a cookout or picnic. It's common to set all the food out on a table and let guests serve themselves over the course of the party. But when the ambient temperature creeps well above room temperature, the amount of time coleslaw and other potentially hazardous foods can be left out begins to plummet.

In the situation of a cookout or other event where coleslaw is exposed to the summer heat (or even left out in direct sunlight), the time it can be out of the fridge is cut in half. After just one hour, you run the risk of encountering food-borne illnesses. And trust us, that hour can go fast when you're enjoying a social event with family and friends. If you're concerned about a particular dish, consider bringing along a meat thermometer and monitoring the temperature on the surface and in the middle of the salad to keep tabs on when the temp is close to crossing into the danger zone.

How Long Does Coleslaw Last?

Assuming that you're storing your coleslaw in the refrigerator — and haven't taken it out for a stretch of time and put it back in — coleslaw can safely last up to five days. However, it's important to remember that this is the maximum amount of time it should be kept. Whether it's spent any notable period of time outside of the fridge and the freshness of the ingredients used are both factors that shorten slaw's shelf life.

If you're unsure, it's always best to err on the side of caution and throw it out. Wasting food is a major bummer, but food poisoning is always worse. A good trick to keep track of the "expiration dates" of your homemade food is to grab a piece of masking tape and a permanent marker, write the date on the tape, and stick it to the bowl or storage container. That way, there's no guesswork and you know exactly when to toss any leftovers.

Can You Freeze Coleslaw?

It is perfectly safe to freeze coleslaw. You can freeze coleslaw without risk as long as the slaw hasn't been left out before freezing and it's thawed slowly in the fridge.

Now, will your coleslaw be just as good once it's thawed? No, most definitely not. Dishes containing mayo are almost always terrible after being frozen. Mayonnaise is made with an emulsification of oil and water (in other words, the microscopic droplets of oil are suspended in the water), which gives the condiment its creamy consistency. When it freezes and thaws, this emulsion is broken, leaving you with a watery, grainy mess.

The disappointing results are compounded in coleslaw, in particular, because of the cabbage. Cabbage releases so much water when cut, and even more when it's frozen and thawed, the salad will be entirely waterlogged. So, if soggy, grainy coleslaw isn't what you're after, then freezing is probably not the best choice.