Your plastic lunch box is why tomorrow's food tastes like fish.

Plastic lunch boxes trap onion, curry, and fish smells because oils and sulfur compounds soak into micro-scratches — glass or stainless steel is the real fix.

The problem isn’t “smelly food,” it’s porous plastic. Onion, garlic, curry, and fish release sulfur compounds that bind to the surface of plastic, especially once the box gets scratched from normal use and dishwashing. Soap and water remove the visible mess, but not what’s absorbed below the surface. That’s why tomorrow’s sandwich tastes faintly of Tuesday’s curry.

The permanent fix is to stop using plastic for strong-smelling food. Glass and stainless steel are non-porous — nothing absorbs, so nothing carries over. Pyrex and similar glass containers are cheap and widely available, and they pop right in the microwave (minus the lid). This is the only thing that actually completely solves it.

If you’re stuck with plastic, your best shot is a baking soda paste scrubbed into the box, a vinegar soak overnight, and then leaving the box in direct sunlight for a few hours. Sunlight genuinely breaks down odor molecules in a way dish soap can’t. Coffee grounds left in a sealed container for a day also work in a pinch, but it’s a band-aid — the smell often creeps back.

Also, always wash the box immediately after eating and dry the lid separately. Letting a curry container sit closed in your bag all afternoon is giving the smell a head start.

Future lunch deserves better than a fishy granola bar.