Thickly branched tree resembling a shrub that may reach several
meters in height. Juniper grows in dry areas in Europe, Asia,
Africa, and North America. It has an irregular stem, leaves terminated by a sharp thorn, and round, blue-violet berries. The berries
are the part used (more or less ripe) wrinkled or dried. Juniper has
an aromatic odor and a bitter taste.
The essential oil should be obtained exclusively by steam distillation of the nonfermented berries; because of extensive gin production (obtained from fermented and subsequently distilled
berries), the oil results as a by-product of gin distillation. The byproduct oil is much less aromatic, lacking the oxygenated fractions. It is almost entirely insoluble in dilute alcohol, even after
subsequent rectification, and is not suitable in the formulation of
compounded oils.
The essential oil obtained by steam distillation of the dried, ripe
berries is a colorless to yellow liquid with characteristic odor and
an aromatic bitter taste.
The oil yield by steam distillation is lower in the case of nonfermented berries (0.5 to 0.6%) as compared to fermented berries
(0.8 to 1.6%). The dried product of Italian origin may yield up to
2.6% essential oil. The oils in general contain P-pinene, myrcene,
d-limonene, cymene, camphene, α- and y-cadinene; the constituents vary, depending on the origin of the plant. The terpeneless or
sesquiterpeneless essential oils are destined for specific applications.
The derivatives are infusion (1 to 3%), distillation waters, distillate
(in 60 to 75% ethanol), and fluid and soft aqueous extracts.
