Why is maple syrup different colors?
The color in maple syrup results from a browning reaction that occurs during the latter stages of evaporation. Sap that is boiled longer makes a darker colored syrup. Therefore, anything that slows the evaporation process, such as uneven or weak fire, an inefficient evaporator, or too much sap in the evaporator, will cause dark syrup. Because color develops during the latter stages of boiling sap, it is particularly important to reduce processing time as the sap approaches syrup. Microorganisms in sap can also cause darkening. Sap flowing into the sap house can be treated with UV light to kill the microorganisms. Sap should be processed as soon as possible after collection to reduce the potential for microorganisms and thus reduce the quality of syrup produced. Syrup may also darken during storage. To prevent darkening, hot syrup that has just been put into containers should be allowed to cool before the containers are packed close together. Gas exchange during storage can also cause s
