You can learn so much science when you're a sugarmaker. For example: the effect temperature has on solubility. To eliminate the naturally occurring salts (maple sand) that fall out of solution when sap is concentrated down to syrup, I filter the product when I transfer it from the big pan to the finishing pan. And when I package the syrup in quart canning jars, it is clear. But as it cools to room temperature more maple sand falls out of solution.
Every time I cook down a batch of maple syrup I am amazed to see high school chemistry in action. One of those concepts actually coming to life.
During this last boil I also investigated whether the boil time effects the color, ie am I burning the syrup while boiling some of the sugars for 10 hours? I did this by keeping the product from the three gallon boil separate from the outside larger 40 plus gallon run. The answer was, for this syrup making session, no. The color was the same. I was a bit surprised by this, sure that some darkening would occur with the longer heating time. In the image below it almost looks like the smaller batch is darker, but I believe that is an artifact of being photographed in front of the other jars.
What I did notice is a shift in syrup coloration -- as usual with the progression of the season.