Caring for food storage containers: stains, smells and warping
How to wash, store and heat food containers so they last, with practical ways to tackle stains and smells and to avoid warped lids.
Published
In The Lid Drawer, a warped lid that has been through a hot dishwasher cycle fits nothing and goes straight in the Trash. In a real kitchen, a bit of care keeps that from happening. This guide covers everyday washing, getting rid of stains and smells, and the heat habits that keep plastic and glass containers in good shape. Always check the manufacturer's instructions for your own containers, since materials and ratings differ.
Everyday washing
Wash containers soon after emptying them. Food that dries on, especially oily or tomato-based food, is much harder to remove later and more likely to stain.
- Use warm soapy water and a soft sponge or brush. Abrasive scourers can scratch plastic, and scratches hold onto stains and smells.
- Pay attention to lid grooves and silicone seals, where food collects. Many seals can be pried out for cleaning; let them dry fully before putting them back.
- Dry containers and lids completely before stacking them. Trapped moisture can lead to musty smells.
The dishwasher
Many plastic containers are labeled dishwasher safe, often top rack only. That advice matters. In many dishwashers the heating element sits at the bottom, so items on the lower rack get the most heat, and thin plastic lids can soften and warp there. A few practical points:
- Put plastic containers and lids on the top rack unless the label says otherwise.
- Wedge light lids in place so they do not flip over and fill with water or fall onto the element.
- If your dishwasher has a heated dry setting, consider turning it off for plastic, or open the door at the end of the cycle and let things air dry.
- Wash takeout tubs and other thin packaging by hand if you keep them at all.
Microwaving safely
Only microwave containers that are labeled microwave safe, and follow any instructions that come with them. A few general habits help:
- Do not microwave takeout tubs, yogurt and margarine containers, or other single-use packaging. They are not designed for heating and can warp or melt.
- Vent or loosen the lid. A tightly sealed lid can trap steam, which can make the lid pop off or deform. Many lids are not meant to go in the microwave at all, even when the container is.
- Watch fatty and sugary foods. They can get much hotter than water-based foods and are a common cause of plastic warping or marking in the microwave.
- If in doubt, transfer the food to a glass or ceramic dish labeled for microwave use.
Freezing
Freezing is gentle on most containers, but a few things make a difference:
- Leave some space at the top. Liquids such as soup and broth expand as they freeze and can crack a container or push the lid off.
- Let hot food cool a little before sealing and freezing it, following normal food safety guidance on cooling leftovers promptly.
- With glass, avoid sudden temperature changes. Moving a dish straight from the freezer into a hot oven, or pouring boiling liquid into cold glass, can make it crack. Let it adjust gradually, and check the manufacturer's guidance.
- The plastic lids that come with glass containers are usually not oven safe, even when the glass base is.
Lifting stains
Tomato sauce, curry and anything with turmeric are the usual culprits for orange stains on plastic. Some approaches people find helpful:
- Baking soda paste. Mix baking soda with a little water, rub it over the stain, leave it for a while, then wash as normal.
- Sunlight. Leaving a clean, stained container in direct sunlight for a day often fades tomato stains noticeably.
- Prevention. Wash stain-prone containers right away, and consider storing tomato-heavy or turmeric-heavy dishes in glass.
Avoid mixing cleaning products, and do not use harsh chemicals on containers that will hold food unless the product is meant for that purpose. A faint stain that will not budge is usually only cosmetic.
Removing smells
Plastic can hold onto strong smells like garlic, onion and fish. To freshen a container:
- Wash it, then fill it with warm water and a spoonful of baking soda and leave it to soak for a few hours.
- A soak in diluted white vinegar works for some smells. Rinse well afterwards.
- Let the container and lid air dry separately and fully, ideally in fresh air.
- Store containers with their lids off or loosely resting on top. A sealed, empty container can trap a stale smell.
If a container still smells strongly after this, it may be time to retire it. Our guide to which containers to keep or recycle can help you decide.
Storing containers so they last
How you store containers affects their lifespan as much as how you wash them. Avoid crushing lids under heavy stacks, which can bend them out of shape over time. Keep containers away from the stove, toaster and other heat sources. Standing lids on edge in an organizer protects them and makes them easier to find. For a full system, see how to organize a food storage container drawer.
Look after your real containers, and leave the warped lids to the game: there is a drawer full of them here.