As temperatures rise again, you might find your produce and bread turning bad more quickly.
That’s partly because of the heat, but humidity has a lot to do with it too. Along with time, acidity and oxygen, heat and moisture are two conditions that encourage the growth of microorganisms that might make you sick.
The widely taught “danger zone” for food safety is the temperature range of 40 to 140 degrees Fahrenheit. But there’s an “amplified danger zone” from 70 to 125 degrees when microorganisms multiply especially fast, and a home could easily reach that temperature, said Kathy Savoie, head of the Maine Master Food Preserver Program.
Here are some factors to keep in mind on hot days.
Dry foods
If you store root vegetables like potatoes or onions outside of the refrigerator, keep them off the floor. This is especially important in a cellar, garage or other space with a cement or dirt floor. Moisture is more likely to come through those floors and get to your food.
In higher temperatures, check your root vegetables more often and remove any that’s starting to rot, because it will spread. If you bought them locally last fall, they’re likely at the end of their readiness anyway, Savoie said.
Bread will likely turn moldy more quickly in these conditions, so you might want to refrigerate it while the heat lasts. Crackers, cereal and other dry foods can get soggy if they aren’t stored in airtight containers, although you can dry them out later in the oven on a low setting.
Make sure your storage area is in a cool, dry part of your house, and increase ventilation if you can. If your home garden is producing more fruit or vegetables than your fridge has room for, look for part of your home with the same characteristics. Use cooler areas and avoid anything that might give off heat, like a water boiler.
Look for nonporous shelf material, like metal, and keep the area ventilated. Dual thermometers that register temperature and humidity are helpful here. If you need extra ventilation, a fan pointed at the shelf can help.
Canned foods
The higher the temperature, the more danger your canned foods will spoil, especially when it’s more than 100 degrees Fahrenheit. Even at 75 degrees, the nutrient content in canned foods will start to decrease, according to the University of Minnesota Cooperative Extension.
An ideal range is from 50 to 70 degrees in a dry, dark area of your home, Savoie said. Storing cans without the screw ring on the top minimizes opportunities for rust, which in a moist environment could break the seal that preserves the food. Then, it’s an opportunity for bacteria, yeast and mold to multiply.
Canned food should also be eaten within a year of processing, she said, and consumed within two weeks of opening.
Refrigerated and frozen foods
You probably know to minimize how much you open your refrigerator on hot days, but if it really can’t keep up, or stops working, put dry ice in it. That can help for three or four days, but make sure you take the proper safety steps, according to the National Center for Food Preservation.
The back of your fridge is colder, according to the USDA, and putting easy-spoiling foods closer to the rear helps.
If your fridge is working hard to run, try cleaning off the coils to help it be more efficient. That area can collect a lot of dust and debris that affects its function, Savoie said.
Dairy products like butter can be left out on the counter, but Savoie recommends only leaving out the amount your family might use in a day rather than a full stick. It can turn rancid after a couple of days.
There’s no way to visually detect most food-borne illnesses, making good storage extra important. In canned foods, at least, look out for bubbling, pressure, broken seals or strange smells.
“When in doubt, throw it out,” she said, an old saying that stays true.
