Already in early spring, the sap begins to flow abundantly through the trees. Before vegetation begins, the sap flows from the roots to the crown of the tree, carrying carbohydrates stored in the roots.
The best conditions are sunny weather and the temperature oscillating around 15°C. The sap flows most abundantly around noon, on the warm side of the trunk when the temperature is the highest. The harvest time is four to eight weeks. The drop in temperature at night slows down the flow of juices.
That's why the march break was invented, so farmers could bring their kids to help with the process of extracting sap from the trees. At least that's what most of them claim :)