Edible common Juniper berries (Juniperus communis) turn from green to dark blue when ripe and to black when dried. To dry them, pick only ripe blue berries and allow to dry. Crush the dried berries well just before using; flavor will decline quickly when exposed to air. Three or four berries should flavor most dishes without being overpowering. Pregnant women and those with kidney problems should avoid Juniper berries due to their diuretic qualities.