This spring, I picked spruce tips, and I'm planning to brew them into a spruce IPA in August. I haven't worked with this ingredient before, and there is somewhat conflicting information on its uses, so it seemed prudent to try to test the ingredient before I actually brewed it into something. Debate on the ingredient has ranged from talk of a guy who uses mature spruce bows in his mash, to discussion of the value of dry hopping spruce, plus everything in between. In particular, and most notably, I found a lot of concern over long spruce boils. Biermuncher made a spruce IPA, which was apparently quite successful, but his tips were much younger than mine. Given so much uncertainty from conflicting information and variation within the ingredient, I decided a test was in order.
The tips were picked from a Norway Spruce, and it was really at the end of the season (late-May, I think). At this point, the tips were almost fully mature in size, but they were still distinguishable from the mature branch. These tips are a lighter green, but, also, when crushed the lighter tips are mild and spicy in comparison to the mature branch, which is bitter and piney. The tips were picked following a heavy rain (this probably makes a small difference), and they've been kept frozen in my chest freezer. Flip over to Biermuncher's thread to see how different my spruce is from his.
Based on what I had read, my impression was that the longer the spruce was boiled, the more spruce flavor/aroma would be imparted and the more bitter it would become.
Statement - "Longer boiling times will lead to more spruce flavor and aroma, but will also create more bitter and unpleasant off-flavors."
Because I wasn't expecting any surprises, I did not structure this scientifically. Really, I just wanted to see how I was going to use the spruce, but I should really go back in future and do this properly. Anyway, I boiled a little spruce (unweighed - maybe an ounce) in a small pot of water (unmeasured - maybe 2-3 cups).
After 5 minutes, I poured a sample, and then I poured another at 10. I then decided I needed to continue the experiment and let it run to 60 before taking a final sample. Boil volume steadily decreased, and there was maybe 1 cup of water left at the end. I can't preclude the possibility that this low volume accelerated any changes in the spruce water.
I ended it up with 3 samples of spruce water. They are displayed left to right - 5 minute, 10 minute, 60 minute.
5 minute - Very pale yellow in color. It might even have a very slight green hint to it. It has a decidedly "fresh spruce" aroma it it literally tastes like I've just popped a fresh spruce tip into my mouth, which is not a good thing. It tastes flat out bad and piney.
10 minute - A pale, but richer yellow. This smells a hair less "fresh spruce" than the 5 minute, but it also has a slightly spicy aroma. It smells nice. It still has a slightly bitter edge to it, but it's much more mild. I basically think this tastes like a tea, and it's not unpleasant. I wouldn't want to drink it by itself, but I think this pretty much maximizes fresh spruce aroma while also leaving you a flavor that can be worked with (unlike the 5 minute).
60 minute - A deep rose color. It actually has a really nice appearance. At this point, most of the spruce aroma is gone. It smells mildly spicy with maybe a hint of spruce. The taste is also very mild - a little sweet and spicy. Blind tested, I wouldn't even guess this is spruce, and it is quite pleasant. I don't know how to describe it except as a mild, sweet herbal tea.
The experiment ran totally contrary to my expectations (hence the write-up). Based on the reading I did, I fully expected the long boil time to make the tea unbearably piney, which was not the case at all. The short 5 minute boil was really bad and overwhelmingly pine, while the 60 minute was quite smooth and mild. Color improved with an increased boil as well, and the 60minute is a really attractive shade of red.
1. Spruce tips do not need to be picked early. Several brewers discussed harvesting as soon as the caps were coming off, and this is not necessary at all. My guess is that the more mature tips lend more flavor (unproven), and late harvest is also now shown to be a low-risk choice.
2. Short boil times are riskier than long boil times! The longer boil makes the spruce more mild, not less. I would guess a long boil would make mature spruce, which is already a bad choice, worse, but that's not what we're talking about.
3. Multiple spruce additions into a boil are not only possible, but are encouraged. The 10 minute had great aroma, but the 60 minute flavor was really top-notch. They would blend really well.
4. 60 minute spruce would be awesome in a winter ale. I'm going to have to try it later this year, but I think you could use a lot of spruce at 60 minutes with very little risk. Again, the full 60 minutes created a very pleasant tea that I think would blend perfectly with the darker malts of a winter ale.
5. Dry hopping spruce is probably not advisable. I haven't tried it, but if a shorter boil is bad, my bet is that dry hopped spruce would be unbearable. Someone should try it, and I'll follow up if I do, but I wouldn't risk it in a batch.
6. My spruce IPA is going to rock.