Juniper berries, from the coniferous juniper tree, are the primary aromatic component in gin.
In cooking, juniper is often used to lend a bright, resinous flavor to fatty, deeply flavored ingredients like wild game, duck, and choucroute (the Alsatian sauerkraut and sausage dish).
Although junipers grow wild in North America, the berries we find in stores are usually dried and imported from Eastern Europe. Dried juniper berries, which look a bit like small, dark blueberries, are available in specialty markets and online at Kalustyans.com.
For the best flavor, buy whole berries and grind them yourself. Like most spices, juniper quickly loses its potency once ground, so grind only as much as you need for a given recipe.
Stored in a tightly sealed container, whole juniper berries will last for up to 2 years.