Perishable foods can spoil or grow harmful bacteria when not stored in the refrigerator or freezer. You’ll want to cook or eat these foods before they go bad, so keeping track of expiration dates is important.
Most of us build our meal plans and grocery lists with some consideration to perishable and nonperishable foods, whether we realize it or not. For the sake of balancing health, taste, and convenience, most home kitchens are stocked with a combination of both types of foods.
To put it simply: Some foods can live in your pantry for months without going bad, while others might last just a few days, even under perfect refrigerator conditions.
Sometimes it’s clear when a food is perishable — most of us know not to keep raw meat in the kitchen cabinet and that canned goods don’t need to be refrigerated. But sometimes, you may find yourself looking at an item, thinking, where am I supposed to store this?
Here’s what you need to know about perishable versus non-perishable food, why this matters, and how to store both safely.
In short, perishable foods are those that spoil or “go bad” quickly if they’re not stored at certain temperatures, whereas non-perishable foods have longer shelf lives and can be stored at room temperature.
What is perishable food?
According to the United States Department of Agriculture (USDA), perishable foods spoil, decay, or become dangerous to eat unless you refrigerate them at 40°F (4°C) or freeze them at 0°F (-17°C) or below (1).
- dairy products
- cooked leftovers
- any fruit or vegetable that has been cut or chopped
Fresh fruits and vegetables are also considered perishable, as very few can be stored for long periods of time at room temperature. Most produce will last anywhere from a few days to a few weeks and should be kept in the refrigerator (3).
What is non-perishable food?
Non-perishable or “shelf stable” foods can be stored safely for long periods of time at room temperature without spoiling or decaying (4).
Examples of non-perishable foods include:
You can keep these foods in a pantry or cupboard.
Keeping perishable foods cold slows bacterial growth and keeps food safe to eat for longer (5).
There are two distinct types of bacteria that grow on perishable foods.
Pathogenic bacteria are tasteless, odorless, and invisible, but can make people sick. Examples of pathogenic bacteria are E. coli, Salmonella, and Listeria. These bacteria grow rapidly at room temperature, and chilling food dramatically slows their growth (
Spoilage bacteria are safe to eat and don’t make you sick, but their presence can degrade the taste, smell, and appearance of food, which can be unappetizing. Refrigeration slows the growth of spoilage bacteria, although they still grow in the refrigerator (
Different bacteria grow at different rates and under different conditions. Food safety standards take the characteristics of many different bacteria and other microbes into account (
Temperatures to store perishable foods
Perishable foods should be stored in the refrigerator at 40°F (4 °C) or below, according to Robert Powitz, PhD, MPH, RS, a sanitarian and advisor to the Indoor Health Council.
“Most bacteria that cause foodborne illness grow well at temperatures between 41° to 135°F (5° to 57°C). This temperature range is commonly referred to as the ‘temperature danger zone,'” Powitz told Healthline.
Bacteria grow rapidly in this temperature range.
“If [perishable] foods are kept in this temperature danger zone for any period of time, disease and spoilage organisms will begin to grow,” Powitz said. “Once established, they can divide [and multiply] in as short as 15 minutes.”
As a general rule of thumb, perishable foods like meat, poultry, fish, eggs, dairy, cooked foods, and cut foods should never be left in the temperature danger zone for more than two hours (8).
The danger zone doesn’t apply to most raw, uncut fruits and vegetables, because they don’t grow bacteria as rapidly as other perishable foods. Still, refrigerating these foods is a good idea because it can slow spoilage.
When foods are frozen and kept at 0°F (-17°C) and below, molecules are slowed down so much that bacteria can’t grow.
That said, once the food is thawed, any bacteria present will start to grow again. And while food can be frozen indefinitely without any safety risk, the quality of frozen food will deteriorate over time due to enzyme activity that’s slowed but not halted with freezing (9).
Temperature isn’t the only factor that determines whether — or how quickly — food will spoil.
“Microbes that can cause disease, or any microbe for that matter, need several critical components and conditions to survive and grow,” Powitz said.
These include moisture, organisms to feed on, time, oxygen (or an absence of oxygen, in the case of some microbes), and the right acidity level, he added.
Non-perishable foods lack some of these critical components, which means they don’t spoil as quickly.
“For example, non-perishable foods, such as crackers, lack moisture; pickling reduces the acidity to a level where organisms will not grow; and hermetically-sealed vacuum packaging removes air,” Powitz said.
It’s a good idea to research how how long your perishable foods may last.
|Time in the fridge
|raw ground meat or stew meat
|raw fish and shellfish
|raw steaks, chops, and roasts
|hot dogs and lunchmeats
|2 weeks unopened or 1 week opened
|chicken, egg, tuna, or macaroni salad
|cooked meat, poultry, or fish leftovers
|eggs (in their shells)
Other tips include:
- Every week, go through your refrigerator and throw out anything that’s been in there for too long (
- Keep your refrigerator clean when storing perishable foods. You should wipe up any spills immediately, then rinse the area with hot, soapy water. And to eliminate odors (which won’t affect food safety but can affect taste), keep an opened box of baking soda on a refrigerator shelf (
- When you buy perishable food, be sure to refrigerate it within 2 hours, or 1 hour if the temperature outside is 90 °F (about 32 °C) or above (10).
- Keep raw meat, poultry, seafood, and eggs separate from all other foods. Keep these foods on the bottom shelf of your fridge to avoid possible contamination (
Perishable foods are those that can spoil or grow harmful bacteria when not stored in the refrigerator or freezer.
Different types of perishable foods have different shelf lives, and it’s important to cook or eat perishable foods before they go bad.
It’s a good idea to keep track of how long foods can last in your fridge and clean it out regularly.
Just one thing
Try this today: Perishable foods start growing bacteria as soon as you take them out of the grocery store refrigerator case. Be sure to refrigerate them at home within two hours of putting them in your cart.