If you've been confused about "spiciness" or "hot" warnings on menus, or maybe you'd like to try some new chile pepper but don't know what to expect, science has your back. Most peppers are rated by Scoville units to explain how hot they are. But that doesn't really tell the true story of what it's like to eat those peppers. Ivette Guzmán and Paul W. Bosland of New Mexico State University led a study that looked into "the complex nature of this sensory experience" to give us more comprehensive descriptions of the effects of capsaicinoids, or chile peppers. They found that capsaicin experience can be measured in five different dimensions.
1) Development Heat sensation can be felt immediately or is delayed by 5, 15, 30 s, or longer.
2) Duration Heat sensation lasts for a short time, disappearing quickly, or may last for many minutes to even hours.
3) Location Where is the heat sensation felt; on the lips, front of the mouth, tip of the tongue, mid-palate, or in the throat.
4) Feeling Heat sensation feels SHARP like pins pricking the area or FLAT like the heat is being smeared or painted on with a brush.
5) Intensity Stated as Scoville Heat Units. Normally measured analytically and recorded in parts-per-million (ppm), then converted to Scoville Heat Units by multiplying by 16. Commercial products are labeled mild, medium, hot, or extra hot, however there are no industry standards for these terms.
Mefite lalochezia proposes another dimension, having to do with the effects of the pepper leaving the body.
The study paper goes on to give us a profile of quite a few different kinds of peppers using the new lexicon. This may be helpful to you in finding your new favorite kinds of chiles. However, capsaicinoids aren't the only ingredient that makes food hot and spicy. There's also horseradish/wasabi, ginger, onion, etc. To get a full profile of a prepared dish, you'd have to have a flavor profile of all the ingredients. -via Metafilter