I have a small hobby operation in NW Wisconsin, and I have a question about a situation that occurs occasionally with my sap. I primarily tap soft maples (red) and use a combination of sap sacks and open buckets. It"s been a cold and snowy spring so far, and last week with the ground being about 90% snow covered, we received a moderate rainfall overnight. The next day when I collected, about 25% of my sacks and buckets contained a light brown sap, or what I call "tea sap". I have experienced this before late in the season as things are starting to wind down, and I always associated it with the onset of buds. But as cold as it's been, everything is completely dormant right now. I mixed the "tea sap" with the clear sap, and boiled it down. The syrup turned out very dark; quite different from the usual amber color I'm used to. In addition, the sugar content of the "tea sap" was considerably lower based on my final yield (I don't measure sap sugar content). I thought the brown color might have something to do with rainfall directly mixing with the sap, but some of my open buckets were clear, and some of the sacks were brown, so I don't see a connection there. In fact, I have 2 taps in one tree, one of which was clear and the other was brown!
Is it possible the surface roots of the trees absorbed the freshly leached rainfall containing tannins and other materials, and started transpiring it right away? That would also explain the low sugar content. Any answers / experiences?? Thanks.