I occasionally brew a wheat rye ale, OG around 1.050, with juniper berries. Sort of a nod to historic Scandinavian brews. Its a great summer beer.
I generally use 1/4 oz. of berries per 5 gallon batch, added to the last 15 minutes of the boil. That gives a very slight flavor that is hard to pick out.
I have used berries picked from junipers growing close to my home in Montana, and berries purchased from the local hippie health food store. I strongly prefer the commercial kind. They are bigger and not nearly as pungent. I believe they are imported from Hungary.
I bruised the berries in a mortar and pestle right before I pitch them into the BK.
Basic recipe for 5 gallons is:
20-30% rye malt
20-30% wheat malt
50% pilsner malt
Double decoction or multi-step infusion mash, with rests at 105°-135°-155°F
1.5 oz. Tettnanger 60 min
0.5 oz Tettnanger 15 min
0.25 oz. Juniper berries 15 min.
German ale yeast ferment at 62°F