Butter starter distillate is a steam distillate of the culture of any or all of the following species of bacteria grown on a
medium consisting of skim milk usually fortified with about 0.1% citric acid: Streptococcus lactis, S. cremoris, S. lactis subsp. diactylactis,
Leuconostoc citrovorum and L. dextranicum. The ingredients contain more than 98% water, and the remainder is a mixture
of a butter-like flavor compound. Diacetyl is the major flavor component, consisting of as much as 80 to 90% of the mixture of organic
flavor compounds. Besides diacetyl, starter distillate contains minor amounts of acetaldehyde, ethyl formate, ethyl acetate, acetone,
ethyl alcohol, 2-butanone, acetic acid and acetoin.
