When purchasing extract, look for products that are labeled "pure" or "natural" so that the product is actually pure vanilla extract. If the flavoring is labeled as "imitation vanilla" it is actually made of all artificial flavoring and will not have the same rich flavor as pure vanilla. Imitation vanilla extract is less expensive than pure vanilla extract but twice as much imitation extract is required to equal the flavor of pure extract. Vanilla extract or single strength vanilla extract is a stronger, liquid form of vanilla flavoring and is often used to flavor brownies, cookies and a variety of cakes. Generally, vanilla extract has been aged from 2 to 6 months and contains a minimum of 35% alcohol. If it does not contain the minimum amount of alcohol, it is considered a flavoring, not an extract. Vanilla essence, double strength extract and double fold vanilla are all stronger forms of the liquid flavoring and should be used sparingly when added to foods. British vanilla essence, however, is the same as single strength vanilla extract. As a guide, approximately 1" of vanilla beans = 2 teaspoons of extract.
Extracts can be stored indefinitely without losing much flavor. Keep the extract in a cool dry area away from heat and direct light in an air tight sealed container.