Calcium concentration in tree sap of five species of Minnesota trees as an indicator of sugar sand

Tree sap can be collected from a variety of species (sugar maple, birch, ironwood, box elder, red maple) in Minnesota. When the sap of sugar maple trees and others are cooked into syrup, a cloudy mixture of minerals precipitates out. This precipitate, called sugar sand, gives syrup an unpleasant taste and can clog up machinery if improperly managed. Sugar sand primarily consists primarily of calcium malate. Thus, calcium concentration can be a good indicator of how much sugar sand would precipitate out if sap is processed into syrup. In general, previous literature has shown that sugar maple sap has the highest calcium concentration, followed by box elder, red maple, and paper birch. The purpose of this study was to determine the possible variations in amount of sugar sand found in syrup produced from different species of trees by measuring the calcium concentration in the trees’ sap. In addition, we aimed to determine the pattern of change in concentration of calcium over the course of the season (from March 21 to late April). Two trees each of the five following species were tapped: (Acer saccharum), box elder (Acer negundo), red maple (Acer rubrum), paper birch (Betula papyrifera), and ironwood (Ostrya virginiana). Trees were tapped with 5/16 spiles using standard procedures and the sap collected daily. The volume was measured and calcium concentration of the sap measured using a ion-selective calcium electrode. Results will be presented