According to testers at Cook's Illustrated, pure vanilla has close to 250 natural flavor and aroma compounds compared with one chemical in imitation vanilla. But that doesn't mean that the testers always chose pure vanilla for cooking; they found that different vanilla extracts worked for different purposes. Both taste and personal preferences come into account when you make your choice between the two extracts.
Pure Vanilla Extract
Pure vanilla extract is expensive for a reason. It comes from an orchid whose blossoms must be hand-pollinated because they open only one day per year, and manufacturing the extract takes about 8 months of drying and aging. By law, pure vanilla must contain 13.35 ounces of vanilla beans per gallon of liquid, water and alcohol, used in the extraction process. The naturally brown extract that you buy in stores has a deep vanilla flavor with hints of what the Cook's Illustrated testers described as honey, maple and licorice.
While pure vanilla extract comes from orchids growing in Madagascar, Mexico and Tahiti, imitation vanilla comes primarily from byproducts from the paper-making industry and contains artificial flavorings, but no alcohol. Imitation vanilla has a strong vanilla taste and aroma, but it also typically has a bitterness that reminded the Cook's testers of medicine. Vanilla flavoring describes a product that contains a blend of pure and imitation vanilla.
Uses for Vanilla
Because many of the minor flavor compounds in pure vanilla burn off at between 280 to 300 degrees Fahrenheit, according to Cook's Illustrated, it's hard to tell the difference between the two types of vanilla once they're baked in cookies, which typically get above those temperatures. On the other hand, cakes, puddings and custards all remain below 280 F and all taste better when you use pure vanilla instead of imitation vanilla.
Choosing Pure or Imitation Vanilla
Pure vanilla costs about twice as much as imitation vanilla, according to Sharon Tyler Herbst and Ron Herbst, authors of The Deluxe Food Lover's Companion. If you're on a tight budget, you may need to let cost guide your choice. But if you don't need to keep a close eye on your budget; if you like a glass of warm milk with a teaspoon of vanilla before going to bed; if you prefer a natural product; or if you frequently bake from scratch, you'll want to buy pure vanilla instead of the artificial variety.