Tuesday, February 5, 2013

Beyond maple syrup

Spiles: (L to R) elderberry, sumac, late 1800s model, 1950s model
What: 3 years ago, one of my students told me about her family's sugaring operation in New York. While talking to her I realized I'd never had straight sap before. That semester, Bekah brought me a 20 oz bottle filled with the sweetest water I'd ever had. Wanting to tap my own trees, the following year I bought some spiles (the taps) and buckets. I don't have any sugar maples (Acer saccharum) in my backyard so I decided to try and eke some sweet syrup out of the trees I do have.

Embarassingly out of focus shot of the ESS group
carving their own sumac/elderberry spiles 
Yesterday, with the Earth Skills Seminar, we tapped 13 different species:
  • Norway maple** (Acer platanoides)
  • Boxelder (Acer negundo)
  • Silver maple (Acer saccharinum)
  • Red maple (Acer rubrum)
  • White ash (Fraxinus americana)
  • Apple (Malus domesticus)
  • Big-toothed aspen (Populus grandidentata)
  • Black cherry (Prunus serotina)
  • Hackberry (Celtis occidentalis)
  • Black locust** (Robinia pseudo-acacia)
  • Smoke tree** (Cotinus sp.)
  • Black walnut (nigra)
  • Paper birch (Betula papyrifera) Zac thinks it's a gray birch, but we'll see.  

We're planning on tapping European larch (Larix decidua), red oak (Quercus rubra), staghorn sumac (Rhus typhina)**, and a buckthorn (Rhamnus cathartica)** as well.

** I would categorize all of these species as potentially disgusting to mildly toxic. Both smoke tree and staghorn sumac are in the cashew family (Anacardiaceae), and members of this family have sap that is purportedly toxic. So rather than attempt to make syrup out of the more toxic species, one of my hopes is to get a sense of when the different species have their sap flow relative to the other species. From here, I'd like to find correlations to different characteristics of each species (like habitat range, simple vs compound leaves, ring-porous vs diffuse porous, etc.).

I'll post results of our experiment as they emerge!

Also, I included Norway maple in this list even though the sap is perfectly edible. Trees get "buddy" by the end of the season as they shift from sending sugar/nutrients from the roots up to the twigs to producing chemical defenses. During the summer a broken Norway maple leaf stem will ooze a milky white sap, which tastes terrible. As the early spring sap flow progresses, the sap of Norway maple shifts to being murkier and fouler. I would assume that at this time they're ramping up defenses for the emergence of flying insects and other would-be predators.

Other notes: One thing we said at the Earth Skills Seminar today is that we won't talk about edible/medicinal things that we haven't ourselves tried. I read a lot of bogus stuff on the internet about different saps - a lot of people just citing other unreliable sources. What we hope to do here is take calculated risks to know for myself what is and what isn't a reliable source of sap each spring.


  1. Isn't black cherry sap toxic too? Or just too bitter to possibly eat? I know some parts of cherry plants have arsenic...

    1. I'm not sure - it's all an experiment! One thing I do know is something like Norway maple sap is toxic. But the sap earlier in the flow is still edible (and quite delicious). I think the tree initially pumps all its resources into getting the sap up from the roots into the crown. Then, as temperatures warm (and flying insects emerge), the plant ramps up its chemical defense production. That's when sap starts tasting "buddy" and something like Norway maple gets inedible. I wonder if it's the same for cherry? I'll let you know!

  2. It's no surprise that you never followed up with any results. Blogs never keep promises.

    1. Thanks for keeping me honest. For the most part, we didn't really get any worthwhile flow, which was interesting. I'm not sure if we tapped too late, didn't leave the taps on long enough (we left them until about bud burst for each species). Early season boxelder and norway maple are decent additions to the repertoire. Silver maple's good too. Hickory, oak, and walnut were all fantastic, but we only got a real little bit of sap. Birches were okay, but not much sap flow and takes a lot to boil down. This year I stuck to walnut, Norway, and boxelder out of convenience. Overall, not much of a scientific study, so negative results in this case are not really results.

      And blogs don't make promises, but bloggers can. Maybe I just don't operate on the same time scale as will satisfy your curiosity, Anonymous.

    2. oh dear, the trolls found even this little blog. Did you ever tap any Norways? I have heard both that the sap is decent and awful for syrup

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