Originally Posted by
DrTimPerkins
Good to hear that your season is going well.
Buds don't really affect flavor....until they do....meaning that when it turns buddy, the season is basically done. Almost like a switch, although sometimes there is a little "pre-bud" and sometimes (rarely) a real cold snap can cause the a slight buddy off-flavor to recede temporarily. This is caused by a change in the amino acid composition in the sap due to bud development. Active buds release a suite of amino acids into the sap.....which make the sap taste terrible. They do this only at and after budbreak. Any "pre-bud" flavor is due to some trees in the system having started to bud, but most have not. Usually it's just a short time period before they all pop.
Regular flavor development in syrup is fairly complex, however it is the microbes in the system converting sucrose to invert sugar, and the combination with various amino and organic acids in sap that results in darker color/stronger flavor (one of the most common organic acids is malic acid....the compound which also gives apples their tartness....malic acid is a major constituent of niter -- calcium malate). More microbes when it is warm, thus darker syrup. When you have a cold snap, you kill off some of the microbes, therefore less sucrose inversion so the grade comes back up. In rare circumstances, near the very end, the sap pH can get so low that the color can lighten due to reduced "alkaline degradation" during boiling. That'll make light syrup with a not so great flavor.