The capsicum family includes peppers from temperate to eye-popping; the more capsaicin, the hotter the pepper. Smaller peppers tend to have more zing because of the seeds-and-veins-to-flesh ratio. Capsaicin, while concentrated in peppers' seeds and veins, is present to a lesser degree in the fruit's flesh.

A pepper's Scoville rating, named for pharmaceutical chemist Wilbur Scoville who devised the classic heat test, provides a temperature guide. Higher numbers are hot, hot, hot.

Scoville Unit

Peppers

350,000-500,000

Red habanero

100,000-350,000

Thai, Scotch bonnet, African birdseye, some habaneros

50,000-100,000

Chiltepin, santaka

30,000-50,000

Cayenne, piquin, tabasco

15,000-30,000

de Árbol

5,000-15,000

Serrano, aj amarillo

2,500-5,000

Jalapeño, chipotle

1,000-2,500

Ancho, guajillo, pasilla

500-1,000

New Mexican, poblano

0-100

Sweet bell, pimiento, U.S. paprika

—D.N.