Airtight Stainless Steel Canisters

Details

Dabbas that keep atta and dal dry through a Gaya monsoon: SS 304 body and lid at 0.7 mm, an airtight clamp, and a food-grade silicone gasket that lifts out with a fingernail. Stainless steel with no number after it is the defining cheat in this whole department, and it is a legal one. BIS runs two raw-material standards for utensil steel side by side: IS 5522, which covers the austenitic grades including 304, and IS 15997, which covers six low-nickel austenitic grades carrying 0.2 to 6 percent nickel where 304 carries 8 to 10.5, with manganese raised to make up the difference. Both are legitimate, both can end up under an ISI mark on the finished article, and both reach you described as stainless steel. The low-nickel ones dull, stain and pit after a year of salt and tamarind. A magnet will not separate them, because both are austenitic and both are nearly non-magnetic, so the magnet test that everyone repeats does not answer this question at all. An alloy check does, and ours runs on finished pieces. On a storage dabba this matters more than it does on a pan, because a canister holds salt and masala for months at a stretch and salt is exactly what finds the weakness in a low-nickel grade. The test you can run at home is slower and it works: put a pinch of salt and a few drops of water in the piece, cover it, leave it two days. SS 304 comes out unmarked. A low-nickel grade shows pinpoint pitting or a brown bloom that will not polish out. The second cheat is smaller and more annoying: a steel body with a plastic lid or a plastic clamp, sold as a steel dabba. Plastic goes brittle at the hinge in two or three Indian summers, it holds the smell of hing, and haldi stains it orange for good. There is no plastic on this at all.

• SS 304 body and lid, 0.7 mm, alloy-checked on finished canisters rather than on the coil
• Not a low-nickel IS 15997 grade, and the salt test above will tell you the same thing at home in two days
• Food-grade silicone gasket, lifts out for cleaning, Rs 60 a spare, stocked in every size
• Airtight clamp closure in steel, opens one-handed, no plastic hinge to go brittle
• Opaque, which keeps light off spices and is the reason ground masala stays potent longer in steel than in glass
• No colour transfer from haldi and no retained smell from hing, because there is no polymer for either to get into
• Nests inside the next size up when empty
• ISI marked to IS 14756, the stainless steel utensils standard
• Weights and dimensions published: 500 ml is 10 cm across and 9 cm tall, 1 L is 12 by 12, 2 L is 14 by 16
• It is airtight and moisture tight, not liquid tight upside down. It is a dry-goods dabba and thin dal will find the gasket seam if you lay it on its side
• You cannot see what is in it. Steel and visibility are a genuine trade, which is why the glass jars sit on the same shelf