# What gives vomit its distinctive smell? **URL:** \ **Category:** Factual Questions\ **Created:** [June 9, 2007, 1:00pm UTC](https://boards.straightdope.com/t/what-gives-vomit-its-distinctive-smell/407356 "2007-06-09T13:00:02Z")\ **Posts on this page:** 16\ **Page:** 1
**Author:** ![twickster](https://avatars.discourse-cdn.com/v4/letter/t/ec9cab/32.png) [@twickster](https://boards.straightdope.com/u/twickster)\ **Post date:** [June 9, 2007, 1:00pm UTC](https://boards.straightdope.com/t/what-gives-vomit-its-distinctive-smell/407356/1 "2007-06-09T13:00:02Z")
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? ---
**Author:** ![Argent\_Towers](https://avatars.discourse-cdn.com/v4/letter/a/e8c25b/32.png) [@Argent\_Towers](https://boards.straightdope.com/u/Argent_Towers)\ **Post date:** [June 9, 2007, 1:44pm UTC](https://boards.straightdope.com/t/what-gives-vomit-its-distinctive-smell/407356/2 "2007-06-09T13:44:38Z")
Stomach acid? ---
**Author:** ![Ludovic](https://avatars.discourse-cdn.com/v4/letter/l/7ab992/32.png) [@Ludovic](https://boards.straightdope.com/u/Ludovic)\ **Post date:** [June 9, 2007, 1:49pm UTC](https://boards.straightdope.com/t/what-gives-vomit-its-distinctive-smell/407356/3 "2007-06-09T13:49:08Z")
I second the stomach acid. Actual acids sometimes have that smell to them, too (e.g vinegar.) ---
**Author:** ![R.P.McMurphy](https://avatars.discourse-cdn.com/v4/letter/r/7993a0/32.png) [@R.P.McMurphy](https://boards.straightdope.com/u/R.P.McMurphy)\ **Post date:** [June 9, 2007, 1:54pm UTC](https://boards.straightdope.com/t/what-gives-vomit-its-distinctive-smell/407356/4 "2007-06-09T13:54:43Z")
I don’t know but Jelly Belly actually makes a candy that tastes like vomit. [Jelly Belly gross flavors](http://jellybelly.com/Cultures/en-US/Shop/CandyDetails.htm?CS_ProductID=1064337&CS_Category=BertieBotts&CS_Catalog=B2C) Maybe you should ask them. When I read that it almost made me . . . ---
**Author:** ![Joey\_P](https://avatars.discourse-cdn.com/v4/letter/j/919ad9/32.png) [@Joey\_P](https://boards.straightdope.com/u/Joey_P)\ **Post date:** [June 9, 2007, 2:18pm UTC](https://boards.straightdope.com/t/what-gives-vomit-its-distinctive-smell/407356/5 "2007-06-09T14:18:19Z")
[QUOTE=Spartydog] I don’t know but Jelly Belly actually makes a candy that tastes like vomit. [/QUOTE] I have that, it tastes like shi…er..puke. ---
**Author:** ![Fear\_Itself](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/fear_itself/32/19637_2.png) [@Fear\_Itself](https://boards.straightdope.com/u/Fear_Itself)\ **Post date:** [June 9, 2007, 2:24pm UTC](https://boards.straightdope.com/t/what-gives-vomit-its-distinctive-smell/407356/6 "2007-06-09T14:24:10Z")
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](http://en.wikipedia.org/wiki/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. ---
**Author:** ![Capt\_B.Phart](https://avatars.discourse-cdn.com/v4/letter/c/9fc29f/32.png) [@Capt\_B.Phart](https://boards.straightdope.com/u/Capt_B.Phart)\ **Post date:** [June 9, 2007, 3:05pm UTC](https://boards.straightdope.com/t/what-gives-vomit-its-distinctive-smell/407356/7 "2007-06-09T15:05:45Z")
And if you’ve ever thought parmesan smells of puke - you’re right:- > [@](#): > > For example, when isovaleric + butyric acid was called “parmesan cheese” it inspired participants to say they would like to eat it, while when it was given the negative label “vomit” it provoked the wish to escape from it. The effect was so strong for certain odors, that participants could not believe that the same odorant had been presented to them at both sessions. [From here](http://www.senseofsmell.org/feature/odor/odor_whitepaper_3.php) ---
**Author:** ![twickster](https://avatars.discourse-cdn.com/v4/letter/t/ec9cab/32.png) [@twickster](https://boards.straightdope.com/u/twickster)\ **Post date:** [June 9, 2007, 11:51pm UTC](https://boards.straightdope.com/t/what-gives-vomit-its-distinctive-smell/407356/8 "2007-06-09T23:51:04Z")
Thanks, all. So if what I smelled wasn’t vomit, it was probably parmesan cheese or jelly beans? Interesting… ---
**Author:** ![Janx](https://avatars.discourse-cdn.com/v4/letter/j/b9bd4f/32.png) [@Janx](https://boards.straightdope.com/u/Janx)\ **Post date:** [June 10, 2007, 12:01am UTC](https://boards.straightdope.com/t/what-gives-vomit-its-distinctive-smell/407356/9 "2007-06-10T00:01:11Z")
Yeah, this is a hijack, but I just had to say, > [@Spartydog](#): > > I don’t know but Jelly Belly actually makes a candy that tastes like vomit. 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](http://jellybelly.com/Cultures/en-US/Fun/Flavor+Guides/Bertie+Botts+Flavor+Guide.htm) Janx ---
**Author:** ![Gfactor](https://avatars.discourse-cdn.com/v4/letter/g/9de053/32.png) [@Gfactor](https://boards.straightdope.com/u/Gfactor)\ **Post date:** [June 10, 2007, 12:14am UTC](https://boards.straightdope.com/t/what-gives-vomit-its-distinctive-smell/407356/10 "2007-06-10T00:14:15Z")
[QUOTE=twickster] Thanks, all. So if what I smelled wasn’t vomit, it was probably parmesan cheese or jelly beans? Interesting… [/QUOTE] Or Noni fruit: [Vomit Flower Power: Can A Taste For Poison Drive Speciation? | ScienceDaily](http://www.sciencedaily.com/releases/2007/04/070424083300.htm) ---
**Author:** ![WarmNPrickly](https://avatars.discourse-cdn.com/v4/letter/w/d78d45/32.png) [@WarmNPrickly](https://boards.straightdope.com/u/WarmNPrickly)\ **Post date:** [June 10, 2007, 12:21am UTC](https://boards.straightdope.com/t/what-gives-vomit-its-distinctive-smell/407356/11 "2007-06-10T00:21:05Z")
> [@](#): > > Gastric acid is primarily hydrochloric acid, which doesn’t not smell like vomit. 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. ---
**Author:** ![Rysto](https://avatars.discourse-cdn.com/v4/letter/r/ecccb3/32.png) [@Rysto](https://boards.straightdope.com/u/Rysto)\ **Post date:** [June 10, 2007, 12:24am UTC](https://boards.straightdope.com/t/what-gives-vomit-its-distinctive-smell/407356/12 "2007-06-10T00:24:44Z")
[QUOTE=Spartydog] I don’t know but Jelly Belly actually makes a candy that tastes like vomit. [Jelly Belly gross flavors](http://jellybelly.com/Cultures/en-US/Shop/CandyDetails.htm?CS_ProductID=1064337&CS_Category=BertieBotts&CS_Catalog=B2C) Maybe you should ask them. When I read that it almost made me . . . [/QUOTE] 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.” ---
**Author:** ![monstro](https://avatars.discourse-cdn.com/v4/letter/m/ba9def/32.png) [@monstro](https://boards.straightdope.com/u/monstro)\ **Post date:** [June 10, 2007, 1:17am UTC](https://boards.straightdope.com/t/what-gives-vomit-its-distinctive-smell/407356/13 "2007-06-10T01:17:42Z")
Butyric acid is also what makes a ginko tree stink when it’s horny. ---
**Author:** ![twickster](https://avatars.discourse-cdn.com/v4/letter/t/ec9cab/32.png) [@twickster](https://boards.straightdope.com/u/twickster)\ **Post date:** [June 10, 2007, 12:20pm UTC](https://boards.straightdope.com/t/what-gives-vomit-its-distinctive-smell/407356/14 "2007-06-10T12:20:58Z")
[QUOTE=monstro] Butyric acid is also what makes a ginko tree stink when it’s horny. [/QUOTE] Ginkgo fruit smells more like dogshit to me. ---
**Author:** ![Alive\_At\_Both\_Ends](https://avatars.discourse-cdn.com/v4/letter/a/73ab20/32.png) [@Alive\_At\_Both\_Ends](https://boards.straightdope.com/u/Alive_At_Both_Ends)\ **Post date:** [June 10, 2007, 1:03pm UTC](https://boards.straightdope.com/t/what-gives-vomit-its-distinctive-smell/407356/15 "2007-06-10T13:03:06Z")
[QUOTE=twickster] Urine and feces also have pretty standard smells [/QUOTE] So they do. Does anyone know what, chemically speaking, causes those? ---
**Author:** ![Fear\_Itself](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/fear_itself/32/19637_2.png) [@Fear\_Itself](https://boards.straightdope.com/u/Fear_Itself)\ **Post date:** [June 10, 2007, 1:21pm UTC](https://boards.straightdope.com/t/what-gives-vomit-its-distinctive-smell/407356/16 "2007-06-10T13:21:17Z")
[QUOTE=Alive At Both Ends] So they do. Does anyone know what, chemically speaking, causes those? [/QUOTE] The smell of shit is due primarily to [indole](http://en.wikipedia.org/wiki/Indole) and [skatole](http://en.wikipedia.org/wiki/Skatole).