Materials

Every product we sell is made of one or more of the materials below. Each page says what the material is, where it shows up in the kitchen, how to care for it, and which claims it can and can't support. Start here if a product page names a material you don't recognize.

304 stainless steel (18/8)

The standard stainless for bottles, French presses, bowls, and food service gear, with about 18 percent chromium and 8 to 10 percent nickel.

316 stainless steel

304 with a little molybdenum added for better resistance to salt and acid, used for some cookware cooking surfaces and a few bottles.

430 stainless steel (18/0)

A magnetic, nickel-free stainless used for induction base plates, cookware exteriors, and bakeware, not for parts that hold liquid.

Carbon steel

Bare iron with about 1 percent carbon that builds a seasoning layer with use, found in fry pans, woks, and crepe pans.

Cast iron

Thick, heavy cast metal that is either seasoned bare or coated in fused glass enamel, found in skillets, Dutch ovens, and griddles.

Borosilicate glass

Glass with boron oxide that handles sudden temperature changes well, used in pour-over servers, drippers, and siphon brewers.

Soda-lime glass

The everyday glass of bottles, drinking glasses, and jars, often tempered for strength and more sensitive to heat shock than borosilicate.

Unglazed stoneware

Fired clay with no glaze, so the clay body itself touches food, found in some brewers and baking stones.

Glazed stoneware

Fired clay with a glass-like glaze that touches food, found in mugs, cups, drippers, and plates, and listed here only with lead and cadmium test documentation.