Sulfur Stinks

Cow manure. Garlic breath. Asparagus pee. What do they have in common?

They all stink. And that stink comes from sulfur.

Hydrogen sulfide is a very pungent gas that forms when plant matter decomposes, and gives its telltale fragrance to sewage, rotting garbage, and swamps.

Sulfur dioxide – the smell of burned matches – is a gas produced when fossil fuels burn, metals are smelted, volcanoes erupt or hot springs bubble up.

Organosulfur compounds -- there are millions in nature -- create some of its most repellent aromas. Like a skunk’s spray or the eye-watering fumes of freshly chopped onions.

The ancient Greeks burned sulfur as a fumigating pesticide to kill insects and rodents. When combined with water, sulfur fumes become acid rain.

But sulfur is not all bad news. In fact, it’s essential to life on Earth.

Sulfur is a key component of two essential amino acids, cysteine and methionine, which are building blocks for proteins.

Cysteine helps produce collagen and beta-keratin, proteins found in skin, hair and nails. Methionine protects cells from damage.

Plants too require sulfur, to make chlorophyll and fix nitrogen, which is why it’s used as fertilizer.

Legumes use sulfur to make their protein. Cruciferous plants, like cabbage and broccoli, get from sulfur their signature flavor – and of course, their stinky aroma.