For soup, get a thermos. For yogurt, a thermos works too.

The most reliable leak-proof lunch container for soup or yogurt is a wide-mouth vacuum-insulated thermos, and the Thermos brand is still the safest bet.

I’m not talking about those bento boxes with the snap-lock lids and silicone gaskets. They’re fine for dry food and maybe a slightly damp slice of apple, but they are not truly leak-proof for liquids. Yogurt will find that little hinge gap, and soup will escape the first time the lid gets knocked sideways in a backpack. A thermos uses a threaded screw-on cap, sometimes with a gasket, and that’s a completely different league of sealing.

Get a wide-mouth Thermos or Stanley food jar in 16 or 24 ounces. You can fill it with hot soup and it’ll still be hot at lunch. You can fill it with yogurt and it stays cold and stays inside. Wash it out, and it’s the same container for tomorrow’s chili or leftover curry. The wide mouth makes it easier to eat straight out of, and it’s a lot nicer than trying to scrape yogurt from the bottom of a narrow bottle.

Sure, a glass mason jar is also leak-proof if you get the right lid, but it’s fragile, heavy, and doesn’t keep anything hot. A thermos does it all.

Don’t trust a clip-lock lid with your lunch bag. Your bag and your clothing will thank you later.