Summertime brings opportunities for sunny porch parties and backyard hangouts. Unfortunately, it also brings opportunities for leaving food out at warm temperatures—temperatures that could end up making that food unsafe to eat.
What's the problem with leaving food out?
Some foods provide the right environment for pathogens—harmful bacteria and viruses—to grow. They are usually moist foods full of carbohydrates or protein that pathogens thrive on. These foods are called Time/Temperature Control for Safety (TCS) foods, and they include:
- Cut tomatoes and leafy greens
- Sliced melons
- Cooked vegetables
- Eggs, meat, and dairy products
- Foods labeled “perishable" or “keep refrigerated"
Pathogens grow quickly in these foods when left at room temperature. With enough pathogen growth, a food can make the people who eat it sick. However, keeping food at cold temperatures can slow down pathogen growth. That's why food stays safer for longer when it's kept in a fridge or freezer. This only works if your fridge is cold enough, though—fridges should be at 41° Fahrenheit (5°C) or lower. Hot temperatures—135°F (57°C) or hotter—also restrict pathogen growth.
How long can I leave food out?
The rule of thumb is this: TCS foods are safe without any temperature control for up to four hours. If the ambient temperature is 90°F (32°C) or hotter, that time frame shrinks to one hour. At that point, food has generally “gone bad" and is likely to make people sick if they eat it. There is one exception to this rule: if cold food doesn't get hotter than 70°F (21°C), it can stay out for six hours.
Additionally, opened packages of food or leftovers should only stay in the refrigerator for up to seven days. Remember, cold temperatures only slow down pathogen growth; it doesn't stop it entirely. Even in the fridge, pathogens can eventually grow to dangerous levels.
Use these tips to cut down on spoilage and prevent unnecessary food waste:
- After grocery shopping, put away refrigerated and frozen foods as soon as you can.
- Store newer foods behind older foods so you'll be sure to use the older foods in the fridge first.
- If you're preparing food for a long time, keep TCS ingredients in the fridge until you're ready to use them.
- Never leave frozen food on the counter to thaw; thaw it in the fridge or under cool running water instead.
- Use ice packs and coolers to keep food cold when you're on the go.
If food has been out for too long, can I cook or freeze it to make it safe?
Unfortunately, TCS foods that have been out for longer than four hours need to be thrown away. You can't pop them in the freezer to make the pathogen levels go down, and you can't cook them enough to kill the pathogens that have developed.
This is true for food that has gone bad in the fridge, too. If you notice any of these signs of spoilage in your refrigerated foods, they may have to be thrown away:
- Unusual odors or textures
- Meat that doesn't bounce back when pressed
Remember to follow safe time and temperature requirements to keep your food from turning on you this summer! To learn more about how to keep food safe at home, check out StateFoodSafety's Food Safety for Home Kitchens Course.
— Diana Shelton
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