Why Do Plastic Containers Hold Onto Smells and Stains?

It's mostly habit and texture. Plastic can develop scratches and a slightly porous, worn surface over time, and those tiny crevices trap food residue, oils, and the compounds behind smells — which is why an old plastic container can smell like last week's curry no matter how you wash it. Plastic also absorbs oils and colors, so tomato sauce leaves an orange tint.

Stainless steel and glass don't have this problem because they're non-porous — there's no microscopic texture for odors and stains to lodge in. They wash completely clean and stay that way. If you're tired of fighting smells and stains, that's the practical case for switching the worst-offending containers to steel or glass. More in steel vs. plastic.

Try Steely stainless steel storage.