Since my most recent blog on Thursday the 26th, the sap has continued to flow. Friday was one of those perfect days for sap with frost the night before and plus 7 degrees and lots of sunshine during the day. Friday night there was a good frost but Saturday was slow to warm up above freezing. However, a low pressure system arrived late Saturday and with no frost the sap ran all night. Today we once again we were in full production..
With the frost on Friday we had a chance to test the idea of partially letting the sap freeze and throwing out the ice as a means of concentrating the sugar in the sap. There are records in the literature of the native people using this technique extensively. On our test pan of sap ice formed on the surface to a depth of 2 cm or about 20% of the overall depth. We discarded the ice and then measured the sap sweetness. The raw sap had a sugar content of 2.4% and the sweetened sap after ice removal 3.1% for a 29% improvement. We then froze some sap in our freezer to 50% ice and the sweetness increased to 4.0% or a 58% improvement .In other words nature is acting as a natural way of concentrating sap to save fuel and boiling time, much like our reverse osmosis system. However, there is a law of diminishing returns.The ice from the thin sheet sheet when melted and tested had no detectable sugar content but the ice from the 50% test had about 1% sugar content. As the ice gets thicker some of the sugar is trapped in the ice and if discarded would reduce the quantity of syrup produced. By running more tests the relationships between sweetness, ice formation,. fuel cost and syrup produced could be established. Without doing all that work, it is safe to say that throwing away a thin coating of ice on a tank or bucket would be beneficial.
Syrup pick up outside the camp is working well with approved social distancing. This will continue for the time being.