Whether you’re packing lunch for your children or craving spreadable butter, determining whether your eats need to be on ice isn’t always straightforward.
“People are confused about which foods require refrigeration,” says registered dietician Keiy Murofushi, Director of Food and Nutrition Services at Cedars-Sinai.
But Murofushi says there’s no need to guess—he walks us through the 6 most common foods people have questions about refrigerating.
What needs to be refrigerated?
Dairy and nut butters are mostly fat so there isn’t a lot of room for bacteria growth.
Even so, if you’re susceptible to infection or battling a disease, such as cancer or HIV, keep butters in the refrigerator whenever you’re not using them. For everyone else, the rules for natural nut butters and dairy butter are somewhat similar: You can leave them out for a short time (say half an hour) so they’re easy to spread. Otherwise, keep them in the fridge.
The exceptions are nut butters that contain a slew of preservatives. Read the label to determine whether those are safe at room temperature.
Eggs create a lot of confusion when it comes to proper storage.
If you walk into a Whole Foods or Sprouts, you may see organic raw eggs stored next to dry goods. The reason? “Most people cook eggs, which kill any bacteria that may have made its way through the porous shell,” says Murofushi.
Once eggs are cooked, reduce your exposure to salmonella and other foodborne pathogens by eating lightly-cooked eggs and those with runny yolks right away rather than cooking and then refrigerating. Hard-boiled eggs should stay cold (45 degrees and below is the safe zone).
Steer clear of raw eggs. “Egg shells are porous, which allow bacteria to seep through. Plus, nutrients bind to raw yolks, so your body can’t absorb them,” says Murofushi.
You might think vacuum-sealed packaging protects cheese from spoiling, but that’s not always the case.
“Soft cheeses that have a lot of moisture in them need to be refrigerated,” says Murofushi. So, feta, brie, goat, mozzarella—including string cheese—need to stay cold.
On the other hand, hard cheeses, such as Parmesan, Asiago, and hard cheddars may get a pass. But watch out for soft cheddars since they tend to have a lot of moisture. Check labels for information about whether your chosen cheese needs to stay cold.
Most dairy milk, except powdered and evaporated milk, require refrigeration. The same holds true for plant-based milks, such as soy milk, rice milk, coconut milk, and almond milk.
“You’ll see them in both refrigerated and non-refrigerated aisles,” says Murofushi. But even milks you pluck off a non-refrigerated shelf usually require refrigeration after opening. Look near the opening of the carton for refrigeration instructions.
5. Lunch meat
Some deli meats, like salami, for example, may store fine at room temperature while whole, but once you open the package and slice through the meat, all bets are off.
“Meats like salami and summer sausage are not cooked, they’re cured, so they may contain small amounts of organisms like listeria,” says Murofushi. And once the meat is introduced to the air, bacteria can grow. While that may not be a problem for the average healthy person, it could be risky for people who have weakened immune systems.
The one meat you can safely store at room temp: jerky!
6. Odds and ends
Almost any carton, squeeze bottle, or container you buy off the shelf should be refrigerated after opening. That includes things like chicken broth, ketchup, mustard, and salad dressing.
When in doubt, review the storage instructions on the package. Chances are, it will say “refrigerate after opening to maintain freshness.”
When it comes to refrigeration, it’s always better to err on the side of caution. If there’s any chance food could spoil, don’t let it sit at room temperature for more than 2 hours (though 4 is usually fine). Keep perishable items in an insulated bag with an ice brick. You might even consider adding another layer of ice to stay on the cool side.
“If you’re overstuffing a cooler with a lot of food, you may need more ice bricks to keep it safe,” says Murofushi. “The amount of ice you need depends on the amount of space in your cooler, so read the manufacturer’s guidelines.”
Keep in mind, too, that some of the best foods for snacking don’t require any refrigeration at all. Whole fruits, raw vegetables (such as carrots and celery sticks) and certain spreads—including nut and seed butters in individual packages for snacking—can last for hours without refrigeration.