The stink is in the gasket

Your lunch box smells because there’s a rubber seal, gasket, or seam holding onto bacteria that a normal wash doesn’t reach.

Most people run the box under soapy water and call it done. But if it still reeks, you’ve got a biofilm situation going on in the silicone gasket or that crack around the lid. It’s invisible, but it’s absolutely there.

Here’s the fix:

• Pop out the rubber gasket if it’s removable. Wash the box and the gasket separately.
• Make a paste of baking soda and water, scrub it into every seam, let it sit for 10 minutes, then rinse.
• If the baking soda doesn’t kill it, do a vinegar soak: half vinegar, half water, sit for 30 minutes.
• Let it air dry completely — lid off, gasket out — before storing. Bacteria love moisture.

Also, plastic itself absorbs odors over time, especially tomato or curry-based food. If the box is old and the smell is just in the plastic itself, no amount of cleaning will fully fix that. At that point, it’s a lid-gasket design problem and new lunch box time.