Pasilla vs Poblano

Pasilla is a dried chile. The fresh pod is the chilaca, a long, twisted, blackish green pepper of 15 to 23 cm grown mainly in Jalisco, Nayarit and Michoacán, and the INIFAP volume Cultivo del chile en México says nearly all of it is dried. Dried it turns close to black and wrinkles like a raisin, a pasa, hence pasilla. The Poblano is a fresh chile named for Puebla. Dried from red-ripe pods it is the ancho, and a darker, brown-ripening type dried is the mulato. INIFAP puts the whole system in one sentence: poblano, jalapeño and chilaca, once dried, are called ancho or mulato, chipotle and pasilla. Fresh poblanos sold as pasilla in US and some Mexican markets are a labeling error, not a variety.

Both are Capsicum annuum from the species' home ground. Kraft and colleagues (PNAS, 2014) put the domestication of C. annuum in central-east Mexico, from southern Puebla through the Tehuacán valley to southern Veracruz, so the Poblano is named for a state that sits inside the birthplace. INIFAP reports that about half the poblano crop is sold fresh, and that Zacatecas leads Mexico's dried chile trade, where ancho is 42.4 percent of dried production and pasilla 14.0 percent.

On heat the two overlap so closely that the table settles nothing. INIFAP gives the Poblano 1,500 to 2,500 Scoville as its own figure and warns that a poblano occasionally comes out as hot as a jalapeño. The Mexican standard NMX-FF-10 grades first-quality pasilla at 1,000 to 1,500 SHU and reserves the top grade, called flor, for pods over 20 cm. Flavor is the real difference. Pasilla is earthy, with cocoa and dried fruit. Ancho is sweeter and raisin-like. A fresh Poblano is green, mild and vegetal until roasting deepens it. INIFAP offers a field test for the dried pair that is easy to confuse: cut the pod and hold a piece to the light, and ancho glows stained-glass red while mulato reads brown.

Use follows form. The Poblano's thick walls and heart shape make it the classic chile relleno pepper and the source of rajas. Pasilla goes into moles, adobos and salsa borracha, and fried strips of it are the standard garnish on sopa de tortilla in Mexico City. Together with ancho and mulato it forms the dried-chile base of mole poblano. The pasilla de Oaxaca is a separate smoked chile from the Mixe region, which is why INIFAP notes the central Mexican pasilla is sometimes called chile mexicano to keep them apart.

Sources

• Zegbe Domínguez et al., Cultivo del chile en México (INIFAP / Universidad Autónoma de Zacatecas, 2012)
• Kraft et al., Multiple lines of evidence for the origin of domesticated chili pepper, Capsicum annuum, in Mexico, PNAS 111(17):6165, 2014