One tablespoon of fresh lemon juice is equivalent to 1/2 teaspoon of lemon extract. In addition, 1 teaspoon of lemon zest is equal to the same amount of extract.
Lemon extract is a simple replacement for lemon juice or zest. Extract stays fresh longer than fruit, so it is easy and economical to keep on hand. Lemon extract is often used when cooking fish or chicken, preparing jams and baking cookies, cakes and pies. It typically contains alcohol, oil of lemon and water. One teaspoon of lemon extract contains 30 calories and 10 percent of the recommended daily value of vitamin A.