Membrane Contamination Drool

[Mean_Oscar]

Recently, I changed out a membrane and noticed a thicker than water "drool". Tasted it and it was slightly sweet but not unpleasant. There were no ill effects. Saturday, there was a LOT of it in the bottom of a previously frozen 2.5 gallon jug. Again, slightly sweet, drank an ounce that tasted OK and am fine. We had a little black walnut sap in with the maple in that batch. Also, had recently run sycamore through unit where the membrane was changed. Pulled a membrane from another system that was last used to do 20 gallons of pure black walnut. Same substance was found there. Took some of that and put pectic enzyme in it and that (subjectively) stopped the drool effect. Has anybody else ever seen "drooling" membranes?


Syrup demonstrations since 2001
1 350 gpd and 1 600 gpd RO
15 maple taps
Get black walnut and black birch from a crew member
Made sycamore in 2024

[carls47807]

I can’t answer your question but I think it’s awesome that you tasted it not once but twice.

[DRoseum]

I suspect it's spoiled sap. This "snot" can build up in tubing, strainers, ROs etc and is driven by bacteria.

[Gord]

I can’t answer your question but I think it’s awesome that you tasted it not once but twice.

Agreed, very admirable +1

[DrTimPerkins]

Could be pectin, but possibly also ropey sap.