The lid, not the box
Leftovers sit in the fridge for three days pressed against the lid. It is the surface with the longest contact time and the least scrutiny.
Nearly every container on the market — steel or glass, cheap or expensive — closes with polypropylene. Ours closes with 304 steel. See the whole category, lid by lid.
Two materials. Both named.
304 food-grade stainless steel, and one food-grade silicone seal. That is the entire list. The seal is removable, washable, and replaceable — we sell spares for a few euros, for as long as you own the container.
For meal prep and leftovers
Round stacks well and cleans thoroughly — good for soup, sauce, fruit, snacks. Rectangular sits flat in a bag and takes a divider. Between the sizes, most of a week is covered.
Steel is non-porous. Sunday’s ragu does not become Wednesday’s smell.
One honest note about acidic food
Storing tomato, citrus or vinegar dressings in steel overnight is fine. Simmering an acidic sauce in steel for many hours at temperature is a different situation — that is cooking, not storing, and it is the condition the research on metal migration actually studied.
We would rather explain that than pretend the question does not exist. The full answer, including nickel.
And what steel won’t do
It doesn’t go in the microwave. You can’t see through it. It’s heavier than plastic. If those things matter more to you than what your food touches, buy something else — with our blessing.
