Pesto is a type of green sauce almost always made with basil. Basil pesto is usually served on pasta, but it can also be found paired with meat dishes and can even serve as a substitute for red sauce on pizzas. Although it can be expensive to buy in stores, it is not difficult to make at home.
In addition to fresh basil leaves, basil pesto consists of extra virgin olive oil, nuts, garlic, and cheese. Salt and pepper are often also added to taste. Parmesan or Romano cheese are the usual cheeses included in this sauce.
When working with fresh basil, only the leaves are used. Any stems or flower buds should be removed if present. The leaves should also be thoroughly washed before use. Since basil serves as much of the substance for this sauce, the dried or powdered versions should never be used to make basil pesto.
Usually pine nuts are included. Almost any nut may be substituted, however. Walnuts are the most common substitution, but pistachios, almonds, or pecans may also be used. Nuts are sometimes omitted altogether.
If nuts are used, they may be toasted first to add flavor. Toasting nuts is accomplished by placing them in a frying pan with oil and allowing them cook until they emit a nutty or fragrant flavor. They can also be put on a cookie sheet and baked for several minutes.
Generally, basil pesto is made using a food processor. The basil and nuts are combined first. After they are mixed thoroughly, the garlic, normally chopped, is added. The oil is included slowly, while the processor is running. Afterward, salt and pepper are added according to the cook's preference.
Some recipes suggest combining all ingredients at once before turning on the food processor. Others advise stirring in the cheese by hand. If a food processor is unavailable, a blender may also be used but may be less effective at first since blenders work best with wet ingredients.
Basil pesto may be kept in a refrigerator for about a week and can be easily frozen for later use. If freezing, the cheese should be omitted during the initial combining of ingredients and only added once the pesto is thawed and ready for use. Pesto can be frozen in bags, plastic containers, or ice cube trays. When using ice cube trays, the frozen cubed pesto is usually removed and bagged for storage. Frozen basil pesto keeps about six months.