A serrano pepper is a hot chili pepper that is native to the Puebla region of Mexico, where it grows in the foothills and mountains; it also is widely cultivated for commercial sale. The peppers generally are small in size and are green while growing but eventually ripen into a red, yellow or orange fruit. In general, a serrano pepper has a higher level of spicy heat than a jalapeno pepper although, like all peppers, the amount of heat can vary greatly depending on weather, soil conditions and specific cultivars. When used in Mexican cuisine, serrano peppers frequently are used raw in fresh dishes such as salsa and guacamole. They also can be roasted for use in cooked dishes or pickled to make a food known as sport peppers, although serranos are not usually dried because they contain a significant amount of moisture.
One important aspect of a serrano pepper, as with all peppers, is that the amount of heat contained in the ribs of the pepper will vary based on a variety of factors. In comparison to a jalapeno pepper, the serrano can be equally as hot or as much as four times hotter when eaten. There really is no way to test the heat of an individual pepper except to taste it, which should be done before using large amounts of peppers in dished where too much heat could ruin the flavor. Cooking serrano peppers can help to draw out more heat over time, although it also will diminish the light, fresh taste.
One popular use for a serrano pepper is as a spicy ingredient in fresh salsa. A salsa is a combination of tomatoes, onions, peppers and spices such as cilantro. The fresh taste and crisp texture of a serrano pepper adds bite and flavor to the salsa. The skin of the pepper is much thinner than that of many other varieties, so they can easily be diced and added directly to the salsa without the need for roasting to remove the skin.
A serrano pepper also can be pickled, either to preserve some of the freshness of the pepper or to create a snack food. The peppers usually are pickled in a brine of water, vinegar, salt and sugar that has been spiced with black pepper, garlic, cumin and coriander. Pickling can take about a week to finish, and the pickled peppers will keep for a few months when refrigerated.