Olive oil, mainly produced in the Mediterranean area, is popular all around the world as both a cooking oil and a flavoring oil and is often used in salad dressing. The oil can be made in three major types: virgin, which is made naturally; refined, which is chemically treated; and pomace, which is chemically extracted. Olive oil is easiest to make at home the natural way, using common items from your kitchen to extract the oil from the olives.
Make a series of small cuts with a knife in a handful of clean olives, so that the oil can escape through the skin. Place the olives in the bottom of a medium-sized glass. It is best to use a glass that has a stem, such as a wine glass.
Place the glass inside a large jar. On top of the glass, place a small mesh strainer or a punctured jar lid. Make sure that the strainer or jar lid fits the glass, and that there is no danger of it slipping into or out of the glass. Place a smaller glass, such as a shot glass, or another small, heavy kitchen object onto the strainer to hold it down.
Fill the glass with water, all the way to the top until it is overflowing slightly. If necessary, move the shot glass while you work, but do not let too much water flow into the jar when you replace the shot glass.
Let the olives sit for at least a day and a half, until the olive oil separates from the water, rises to the top, and overflows into the jar. Take the glass out of the jar and pour out as much water as possible, so that you have only the oil left in the bottom of the jar.
Flavor the oil, if desired. For a garlic flavor, leave a whole, clean clove of garlic inside the oil for two days. You can also add lemon peel, peppers, basil, rosemary or other herbs to the oil for flavoring.