Botanically chilies are fruits (capsicum family), and were it not for C. Columbus they would be called just that without the suffix “pepper”.
These potent flavouring agents range vastly in “hotness”, depth of flavour, and textures.
They are used fresh, or dried crumbled, or ground. Fresh chillies in stews or sauces provide an herbal fragrance to foods and higher acidity than peppers. Dried chilies contain less acid and can be toasted for yet another taste dimension. Dried chilies are generally used in sauces. Chefs prefer fresh chilies in salads and marinades.
Mostly Central American and Latin cuisines use chilies, but of late North American chefs, looking for new taste sensations, seem to have discovered the power and characteristic of chilies to change the taste of many foods.
The power or “hotness” of chilies is expressed in Scoville Units established by Wilbur Scoville in 1912. A chemist by trade, he used one unit of chili extract to one of water, until the palate no longer could detect the taste. The more water a chilli needed, the higher is its rating.
The power of chilies resides in the membranes and seeds of the fruit. If you want to render any chili less hot, remove membranes and seeds. There are many chillies and Mexican cooks use all (fresh, dried, or powdered) in a range of their specialties. Here are some of the most popular chillies in North America:
Anaheim a.k.a New Mexican pepper is “mild” with approximately 1000 SU and used for lamb and duck.
Poblano (from 1400 – 3100 SU) is dark green, with thick walls and ideal for stuffing and salads. Some frozen food companies’ offer stuffed and breaded frozen poblanos ready to cook. Dried poblano chilies are called ancho.
Guajillo chilies are dark red and available dried.
Jalapeno (from 2600 – 4900 SU) is a small green chili and quite potent. Larger specimens are stuffed with cheese or meat. Smoked jalapeno chillies are marketed as chipotle and that dried en adobo.
Serrano (10,000 – 23,500 SU) are small, the size of the little finger. They are generally pickled to accompany Mexican specialties or used in sauces.
Cayenne (30,000 – 50,000 SU) is mostly dried and ground; often used by European chefs to provide piquancy to sauces and bland foods. Cajun and Latin American chefs use cayenne liberally in their cooking.
Habanero (100,000 – 500,000) originates and is grown in the Yucatan Peninsula, Mexico. This extremely potent, orange coloured chilli tastes fruity and floral. Often used by Latin American cooks.
Scotch Bonnet (more than 100,000) is a relative of Habanero and grows in Jamaica. Both Habanero and Scotch Bonnet chillies are considered the hottest of all chillies and should be used in very small doses.
NOTE: North American palates are less used to “hotness”, and tolerate infinitely small quantities of chilies.
European chefs use very little chilies except for cayenne in certain sauces. Some chefs like to toast ground chilies for yet another taste dimension.