How to store potatoes and onions properly (2026)
Quick Answer
Store potatoes and onions separately in a cool, dark, dry, well-ventilated place, not in sealed bags or near heat and sunlight. Keep potatoes away from onions because onions give off moisture and gases that can make potatoes spoil or sprout faster. Check both regularly and remove any soft, mouldy or sprouting ones before they affect the rest.
Overview
Potatoes and onions both last longer when they are kept cool, dry and out of direct light, but they should not be stored together. The main aim is to slow sprouting and rot while avoiding trapped moisture. Good airflow matters because damp, still conditions encourage mould and soft spots, while too much light can make potatoes turn green and develop compounds you should not eat. A pantry, cupboard, cellar or utility space can work if it stays relatively cool and dry and is not next to an oven, radiator or sunny window. For best results, keep them in separate breathable containers such as mesh bags, baskets, paper bags with holes, or slatted crates. Avoid plastic bags and sealed tubs unless they are specifically designed with ventilation. Do not wash potatoes or onions before storing them, because surface moisture shortens storage life. If you buy produce in bulk, sorting it first is worth the effort: one damaged onion or bruised potato can quickly affect the rest. Regular checks are part of proper storage, especially if your kitchen runs warm or humid. Used this way, simple storage habits reduce waste, keep flavour and texture better, and help you avoid unpleasant surprises when you come to cook.
Who this is for
Anyone storing whole raw potatoes and onions at home, especially if buying in bulk or trying to reduce food waste.
What you’ll need
- A cool, dark, dry storage space
- Separate breathable containers for potatoes and onions
- A tray, basket, crate or shelf that allows airflow
- Paper towel or clean dry cloth for wiping off loose dirt if needed
- Good lighting for checking for damage, sprouts or mould
Before you start
Check that your storage area is away from direct sunlight, cookers, radiators, dishwashers and sinks. Make sure potatoes and onions are whole, dry and not already badly damaged. Plan to store them separately, and do not refrigerate whole onions or raw potatoes unless packaging or official guidance for a specific product says otherwise.
Step-by-step
- 1
Sort them before storing
Spread out the potatoes and onions and inspect them. Remove any that are bruised, cut, leaking, mouldy, unusually soft, or already rotting. Set aside any slightly damaged ones to use first.
Why: Damaged produce deteriorates faster and can speed up spoilage in nearby items.
- 2
Keep potatoes and onions apart
Place potatoes in one container and onions in another, with space between them. Do not pile them into the same basket, sack or cupboard section if you can avoid it.
Why: Onions release moisture and gases that can encourage potatoes to sprout and spoil more quickly.
- 3
Use breathable storage
Store each in mesh bags, open baskets, paper bags with ventilation, or slatted boxes. If they came in plastic, take them out unless the packaging is clearly ventilated and intended for storage.
Why: Airflow helps prevent trapped moisture, which is a common cause of mould, softening and rot.
- 4
Choose a cool, dark, dry place
Put the containers in a pantry, cupboard, cellar or similar space that stays relatively cool and dry. Keep them out of direct light and away from hot appliances and steamy areas.
Why: Cool temperatures slow sprouting and spoilage, darkness protects potatoes from greening, and dryness reduces mould risk.
- 5
Leave them unwashed until use
Do not wash potatoes or onions before storage. If needed, gently brush off loose dirt from potatoes and make sure onions are dry before putting them away.
Why: Extra moisture on the surface shortens storage life and encourages decay.
- 6
Check them regularly
Inspect the stored potatoes and onions routinely. Remove any that have gone soft, mouldy, shrivelled, or have strong off smells. Use sprouting or slightly soft ones promptly if still otherwise sound.
Why: Catching problems early helps stop one spoiled item from affecting the whole batch.
Why this works
Proper storage works by balancing three things: lower light exposure, lower moisture and steady airflow. Potatoes need darkness to avoid greening and a cool environment to slow sprouting. Onions keep best when dry and ventilated. Storing them separately avoids the moisture and gas exchange that speeds deterioration.
Common mistakes to avoid
- Storing potatoes and onions together
- Leaving them in sealed plastic bags
- Keeping them near a cooker, radiator or sunny window
- Washing them before storage
- Ignoring one bad onion or potato in the bag
- Eating potatoes that have turned green in large areas or are badly spoiled
Troubleshooting
Potatoes are sprouting quickly
Move them to a cooler, darker place, improve ventilation, and make sure they are not stored near onions or fruit.
Potatoes are turning green
Reduce light exposure immediately. Trim small green areas generously before cooking if the potato is otherwise sound, but discard potatoes with extensive greening or bitterness.
Onions are going soft or mouldy
Increase airflow, separate any affected onions, and move the rest to a drier location away from damp walls or appliances that create steam.
Both are spoiling faster than expected
Check whether the storage area is too warm or humid, whether they are crowded, or whether damaged items were stored with sound ones.
Compare your options
Open basket or slatted crate
Best for: Pantries and utility rooms with decent airflow
Pros: Good ventilation, easy to inspect contents, simple to use
Cons: Less protection from light unless kept in a dark cupboard
Mesh bag
Best for: Small quantities and hanging storage
Pros: Breathable, space-saving, easy to keep separate
Cons: Light exposure can be a problem if left out in the open
Paper bag with holes
Best for: Cupboards where light control matters
Pros: Reduces light exposure while still allowing some airflow
Cons: Can trap moisture if overfilled or stored in a humid space
Sealed plastic bag or airtight tub
Best for: Generally not recommended for whole raw potatoes or onions
Pros: Easy to contain mess
Cons: Poor airflow and trapped moisture can speed spoilage
| Option | Best for | Pros | Cons |
|---|---|---|---|
| Open basket or slatted crate | Pantries and utility rooms with decent airflow | Good ventilation, easy to inspect contents, simple to use | Less protection from light unless kept in a dark cupboard |
| Mesh bag | Small quantities and hanging storage | Breathable, space-saving, easy to keep separate | Light exposure can be a problem if left out in the open |
| Paper bag with holes | Cupboards where light control matters | Reduces light exposure while still allowing some airflow | Can trap moisture if overfilled or stored in a humid space |
| Sealed plastic bag or airtight tub | Generally not recommended for whole raw potatoes or onions | Easy to contain mess | Poor airflow and trapped moisture can speed spoilage |
Alternatives
- Buy smaller amounts more often if your home is warm or humid
- Use a dedicated ventilated vegetable rack or storage bin
- Store sliced or peeled onions in the fridge only after preparation, following food safety guidance
Pro tips
- Use older stock first so newer purchases do not sit too long
- Label containers with the purchase date if you buy in bulk
- Keep potatoes away from strong light even for short periods
- If your cupboard is dark but stuffy, leave some space around containers for airflow
Safety notes
- Do not eat potatoes with extensive green colouring, bitterness, or severe spoilage
- Discard onions with visible mould deep into the layers, leaking flesh, or strong rotten odours
- Keep stored produce dry to reduce mould growth
- If you have any concern about food safety, follow official food safety guidance and when in doubt, throw it out
What this guide does not cover: This guide covers whole raw potatoes and onions for normal home storage. It does not cover commercial storage systems, peeled or cut produce, preserving methods, or every potato and onion variety.
Cost considerations
Proper storage can reduce waste significantly, especially if you buy larger bags. The main cost is a simple breathable container or better pantry organisation rather than specialist equipment.
Frequently asked questions
Can I store potatoes and onions together if space is tight?+
It is better not to. Even in a small kitchen, separate them into different breathable containers because storing them together tends to shorten shelf life.
Should potatoes be kept in the fridge?+
For whole raw potatoes, a cool dark cupboard or pantry is usually preferred. Refrigeration can affect quality, so check official food guidance if you are unsure about a particular product.
How do I know if an onion should be thrown away?+
Discard it if it is slimy, heavily mouldy, leaking, or smells rotten. A dry outer layer or a small soft spot may only mean it should be used soon if the rest is sound.
Are sprouting potatoes still usable?+
Often they can be used if they are still firm and not green or rotten, after removing the sprouts and any green parts. If they are soft, shrivelled, bitter, or heavily green, discard them.
What is the best container for onions?+
Anything breathable works well, such as a mesh bag, wire basket or slatted crate, as long as the onions stay dry and out of direct light.
Sources & references
Guidance on this page is traced to documented sources. Last checked 24 September 2026.
- Food Standards Agency · government
Supports general UK food safety principles such as discarding unsafe food and following safe storage practices.
- Idaho Potato Commission · industry
Supports practical potato storage advice such as keeping potatoes in a cool, dark, well-ventilated place and avoiding onion co-storage.
Basic home storage guidance for whole potatoes and onions changes slowly, though product-specific advice can differ.