What gives vomit its distinctive smell?

I was driving home from work last night, hot day, car windows open, and passed an area that smelled like vomit. I don’t know whether it was human vomit or not – didn’t see any, but I was going about 45 – but it got me to thinking …

Cat vomit usually appears very soon after the cat eats, and it usually smells like cat food. Human vomit may or may not appear immediately after the human eats, but if there are stomach contents, the vomit usually smells like vomit, not like the particular foods that are (or I guess “had just been”) in the person’s stomach. Urine and feces also have pretty standard smells, but those are end-products, so to speak – vomit would seem to be less “processed” than that. And yet it doesn’t smell like constituent parts, but like vomit.

So what is it that vomit smells like?

Stomach acid?

I second the stomach acid. Actual acids sometimes have that smell to them, too (e.g vinegar.)

I don’t know but Jelly Belly actually makes a candy that tastes like vomit.

Jelly Belly gross flavors

Maybe you should ask them.

When I read that it almost made me . . .

I have that, it tastes like shi…er…puke.

It is not the stomach acid per se, but the products of the action of gastric acid on food. Gastric acid is primarily hydrochloric acid, which doesn’t not smell like vomit. But when it acts on food, it produces chemicals like butyric acid that are strongly associated witht the smell of vomit. Vomit smell is a complex aroma, comprised of many chemicals produced by the action of gastric acid on food.

And if you’ve ever thought parmesan smells of puke - you’re right:-

From here

Thanks, all.

So if what I smelled wasn’t vomit, it was probably parmesan cheese or jelly beans? Interesting…

Yeah, this is a hijack, but I just had to say,

They make booger flavor, earwax, dirt, earth worm … LOTS of fun! (barf!)

http://jellybelly.com/Cultures/en-US/Fun/Flavor+Guides/Bertie+Botts+Flavor+Guide.htm

Janx

Or Noni fruit: Vomit Flower Power: Can A Taste For Poison Drive Speciation? | ScienceDaily

I definitely think that vomit smells somewhat of hydrochloric acid. It’s not the only smell, but the smell is there. Then I’ve smelled a lot of hydrochloric acid in my day, I could be sensitized.

Bertie Botts’ Every Flavour Beans are from the Harry Potter series. As Ron says when they’re introduced, “You want to be careful with those. When they say every flavour, they mean every flavour – you know, you get all the ordinary ones like chocolate and peppermint and marmalade, but then you can get spinach and liver and tripe. George reckons he had a bogey flavoured one once.”

Butyric acid is also what makes a ginko tree stink when it’s horny.

Ginkgo fruit smells more like dogshit to me.

So they do. Does anyone know what, chemically speaking, causes those?

The smell of shit is due primarily to indole and skatole.