I brewed my Spruce IPA last weekend. I kept picking the tips to see what kind of flavor then had. It was so slight that I said screw it, and cut down a few whole branches and took a scissors and pruned two pint cups full of needles, mostly old growth, as those had a ton of aroma and flavor, while the new growth just tasted like grass. I have no idea the exact amount, but i put 1/2 of one cup in a 60min, the other half at flame out. I also put one whole cup in w/ the mash. No idea if it will contirubte anything to the beer, or if i will ever really be able to tell as i used Simcoe and other "piney" hops. My gut tells me I should have used WAY for spruce for it to come threw. I tasted a gravity sample the other day, its piney of course, but from the hops or the actual pine, ill never know.