Extraction techniques
The majority of natural essences are obtained by extracting the essential oil from the blossoms, fruit, roots, etc., or the whole plants, through four techniques:
Expression when the oil is very plentiful and easily obtained, as in lemon peel.
Absorption is generally accomplished by steeping in alcohol, as vanilla beans.
Maceration is used to create smaller bits of the whole, as in making peppermint extract, etc.
Distillation is used with maceration, but in many cases, it requires expert chemical knowledge and the erection of costly stills.
The distinctive flavors of nearly all fruits, in the popular acceptance of the word, are desirable adjuncts to many food preparations, but only a few are practical sources of sufficiently concentrated flavor extract. The most important among those that lend themselves to "pure" extract manufacture include lemons, oranges, and vanilla beans.