Árbol chilies, often sold under the Spanish name chiles de árbol, are medium-sized, thin, dried, hot chili peppers (part of the highly variable species Capsicum annuum). Árbol contribute a sharp, clean flavour to dishes. They’re particularly popular for two key reasons: heat, and colour. Árbol chilies are definitely fiery enough to appeal to fans of spice, without being unbearably overwhelming. The colour is an added benefit, as the bright red of the fresh chili doesn’t darken much with drying, meaning that the chilies lend a glorious red colour to sauces, soups, and more.
The word árbol means tree, a reference to the woody stems on the peppers. Both the Spanish and English names are applied to the fresh and the dried pepper.
Árbol chilies are generally available whole (as shown in the picture), and ground or crushed. Though crushed árbol chilies are fairly popular, it can be difficult to find them specifically labeled as such.
Árbol chilies are sometimes called rat-tail (cola de rata) chilies and bird’s beak (pico de pajara) chilies. They should not be confused with bird’s eye chilies, which are popular in Southeast Asian cooking, and are even spicier.
Scoville Heat Units