Most people don’t realize that the way you store potatoes and onions can make the difference between them lasting a few days or several weeks. Many households throw away potatoes because they sprout, turn green, or become soft, and onions often become moldy or mushy. In many cases, this happens simply because they are stored incorrectly.
If you learn how to store potatoes and onions properly, you will waste less food, save money, and keep your kitchen better organized.
Why Potatoes Need a Cool, Dark, Dry Place
Potatoes are living plant tubers, which means they are still alive even after they are harvested. Because they are alive, they react to light, temperature, and moisture.
Potatoes need a cool, dark, and dry place for three main reasons:
Cool: Warm temperatures cause potatoes to sprout faster.
Dark: Light causes potatoes to turn green and produce solanine, which can taste bitter and can be unsafe in large amounts.
Dry: Moisture causes potatoes to rot and grow mold.
When potatoes are stored in a cool, dark, dry environment, they stay dormant longer and last much longer.
How to Store Potatoes and Onions the Right Way
Best Places to Store Potatoes
- Pantry shelf
- Cabinet
- Basement
- Cool closet
- Paper bag on a shelf
- Basket with airflow
- Cardboard box
These locations keep potatoes away from light, heat, and moisture.
Why You Should NOT Store Potatoes in the Refrigerator
Many people think the refrigerator is the best place to store potatoes, but it actually causes a chemical change inside the potato.
When potatoes are stored in cold temperatures, the starch inside the potato begins to convert into sugar. This is why refrigerated potatoes sometimes taste sweeter and cook differently. When these sugary potatoes are cooked at high temperatures (like frying), they can turn dark brown very quickly.
This is why potatoes should be stored in a cool room, not a cold refrigerator.
Do NOT Store Potatoes:
- In the refrigerator
- In plastic bags
- In direct sunlight
- Near onions
- Near the stove
- Under the sink
- In sealed containers
These environments either trap moisture, expose potatoes to heat, or expose them to light, which causes them to spoil faster.
Why Potatoes Should Be Stored in Paper Bags Instead of Plastic Bags
You may notice that potatoes are often sold in plastic bags at the store, but plastic bags are not good for long-term storage at home.
Plastic bags trap moisture and prevent airflow. When moisture builds up, potatoes begin to rot faster and may grow mold.
Paper bags, mesh bags, cardboard boxes, or baskets allow air circulation. Airflow helps keep the potatoes dry and slows down spoilage.
So yes, this is one reason potatoes sometimes go bad quickly after bringing them home from the store — they are left in the plastic bag where moisture builds up.
Better storage containers include:
- Paper bags
- Mesh bags
- Cardboard boxes
- Baskets
- Wooden crates
Anything that allows airflow is better than plastic.
Learning how to store food properly is one of the easiest ways to reduce waste and save money, especially when you are trying to lower your grocery bill and make food last longer. https://everydayanswers.online/lower-monthly-grocery-bill/
Why Onions Need Airflow and Dry Storage
Onions are different from potatoes. Onions have layers that trap moisture, and if they are stored in a sealed container or plastic bag, that moisture causes mold and soft spots.
Onions need:
- Dry air
- Good airflow
- A cool environment
- No moisture
This is why you sometimes see onions stored in hanging mesh bags — the airflow helps them last longer.
Best Places to Store Onions
- Pantry shelf
- Hanging mesh bag
- Basket with airflow
- Dry cabinet
- Cool room
Do NOT Store Onions:
- In plastic bags
- In sealed containers
- In damp areas
- Near potatoes
- Under the sink
- In the refrigerator (whole onions)
Moisture and lack of airflow are the biggest reasons onions go bad quickly.
Why You Should Not Store Potatoes and Onions Together
Many people store potatoes and onions together in the same basket, but this actually causes both foods to spoil faster.
Onions release moisture and gases that cause potatoes to sprout and rot faster. Potatoes release gases that cause onions to become soft and moldy.
When stored together:
- Potatoes sprout faster
- Onions become soft
- Both spoil faster
- More food waste
- More money wasted
So one of the most important food storage rules is:
Always store potatoes and onions separately.
According to USDA food storage guidelines, potatoes should be stored in a cool, dark place and not in the refrigerator because cold temperatures change the starch inside the potato into sugar. https://www.usda.gov
How Long Potatoes and Onions Last When Stored Properly
If you store potatoes and onions correctly, they can last much longer than most people expect.
| Food | How Long It Lasts |
| Potatoes | 3–5 weeks |
| Onions | 1–2 months |
| Sweet potatoes | 2–3 weeks |
| Cut onions | 7 days (refrigerator) |
| Cooked potatoes | 3–4 days (refrigerator) |
Proper storage can reduce food waste and save money over time.
Signs Potatoes or Onions Have Gone Bad
Bad Potatoes:
- Soft spots
- Sprouts
- Green skin
- Wrinkled skin
- Mold
- Bad smell
Bad Onions:
- Soft or mushy
- Mold
- Slimy inside
- Dark spots
- Strong bad smell
If you notice these signs, it is best to throw them away.
Simple Storage Tips to Make Them Last Longer
If you want your potatoes and onions to last as long as possible, remember these simple tips:
- Keep them in a dark place
- Keep them dry
- Use breathable containers
- Keep them separate
- Do not wash before storing
- Check them once a week
- Remove any bad ones immediately
- Keep away from heat
- Keep away from sunlight
- Store in a cool room
These simple steps can make a big difference in how long your food lasts.
Common Questions About Storing Potatoes and Onions
Should potatoes be stored in the refrigerator?
No, because cold temperatures turn starch into sugar and change the taste and cooking quality.
Can potatoes and onions be stored together?
No, they cause each other to spoil faster.
Why do potatoes turn green?
Light exposure causes potatoes to produce chlorophyll and solanine, which turns them green.
Should you wash potatoes before storing?
No. Only wash potatoes before cooking.
Why do onions get moldy?
Usually because they were stored in plastic bags or damp areas without airflow.
Before You Go (Food Storage Tip for the Week)
Food storage is one of the easiest ways to save money in your kitchen. Many households throw away food simply because it was stored incorrectly. Learning how to store food properly can make your groceries last longer, reduce waste, and help you become more organized and self-sufficient at home.
Reader Question
How do you currently store your potatoes and onions — in the pantry, refrigerator, or on the counter? You might be surprised how much longer your food lasts just by changing where you store it. Try these storage tips this week and see if your potatoes and onions last longer.