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Pine Soap

11-3-17 foam 049A7281

The bubbles you see is are the formation of a crude soap on the bark of a White Pine. During dry periods salts, acids and other particles from the air coat the surface of the bark. When it rains, these mix with the water and form a solution. The foam is from the agitation of the mixture when it encounters a barrier (bark) during its flow toward the ground.

As to why this occurs primarily on pines, botanist Ken Sytsma states, “Pines produce a whole array of natural hydrocarbons for herbivory defense. One set of these is “pine tars” that have been used in the past to make soap. As precipitation works its way down trunks of pines, they accumulate these compounds. What you may be seeing is natural pine soap in the making.” (Thanks to Brenda & Steve Hillier for Mystery Photo idea.)


5 responses

  1. Marilyn


    November 8, 2017 at 9:22 am

  2. Dudley Carlson

    Thank you for a compelling mystery photo – and a wonderful memory. My grandmother always used little round, green soaps stamped with a pine cone and a spray of needles. Their clean pine scent was a treat for a child raised on grocery-store soap, and it still reminds me of her, and of wonderful visits. Who knew that pine trees made their own?!

    November 8, 2017 at 1:21 pm

  3. Ray

    We used to buy pine soap in 55 gallon drums.

    November 8, 2017 at 9:11 pm

  4. Tim

    Thanks. ………I love this sight !!

    November 9, 2017 at 5:57 am

  5. That’s a new one for me, thanks!

    November 10, 2017 at 3:21 pm

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