Crème Yvette is a violet, citrus and vanilla flavored crème liqueur first produced in the 1890's in the United States by the Sheffield Company.
Creme Yvette went out of production, and has recently been revived by the Cooper Spirits Company. It is now made near Bordeaux, France. It is a blend of violet petals, blackberries, cassis, wild strawberry, and raspberry with accents of honey and citrus. This differentiates Crème Yvette from Crème de Violette, which is solely flavored with violets. They are not well substitutable for each other.
Crème liqueurs should not be confused with cream liqueurs, which are made from a base spirit, flavorings, and cream. Crème liqueurs get their name from the syrupy texture that a large quantity of sugar imparts to the liqueur.
While there are many flavors of crème liqueurs, they are all around 30 proof.