Improving color grading of maple syrup
CALS Impact Statement
Practices and equipment used in color-grading maple syrup were evaluated. A significant difference was discovered between the traditional visual method of color matching and the measurement of light transmission by spectrophotometer, a method that is new to the U.S. maple industry. A method to correct differences in grading between the two methods was determined and proposed. We also evaluated visual comparison kits that are widely used in syrup grading and identified potential sources of errors in their use. A workshop on grading methods has been developed and offered to producers as a way to improve their knowledge and skills.
State, federal, and Canadian regulations require that maple syrup be classified (graded) by color. Consumers use color as a general guide to flavor intensity. Color grading is most frequently done visually using one of a number of different grading kits. Canadians use light transmission determined spectrophotometrically as the official method, and low-cost spectrophotometers have recently been introduced for general use. Those adopting this newer approach felt that the two systems were producing different results. If true, this would have regulatory and economic consequences, as higher prices are paid for the lighter grades.
We (Brian Chabot and Stephen Childs) conducted research that determined that visual grading and spectrophotometric grading produce different results. Spectrophotometric grading produces a larger number of syrups in the darker grades. To understand this result we explored the history of syrup grading practices and how color density was being sensed visually and through instruments. Eventually we discovered why and how the difference developed. We have proposed changes to the percent transmission values that would bring the two approaches into closer agreement.
We subsequently conducted research comparing the performance of the variety of visual grading kits in use by the industry. We validated the comparability of these different tools when used appropriately. We identified two factors (background light color and container size) that could produce erroneous results.
In addition to proposing new transmission values for grade determination, we also produced publications and fact sheets that describe best practices in using both grading methods. These have been shared with state and federal regulatory officials in addition to producers. We also have developed a workshop that educates maple producers about all aspects of maple syrup grading as an effort to improve knowledge and practices.
Maple syrup producers have an improved understanding of and improved methods for color-classification of their syrup. No longer can wholesale syrup buyers use the darker grading from spectrophotometric methods as a basis for paying a lower price for syrups. New York, U.S., and Canadian regulators have the information needed to change the transmission values being used to define the several color classes.
The daylong workshop on grading practices reached 80 producers in 2006, and more workshops have been scheduled for the future. This workshop is leading producers to a deeper understanding of the techniques and technology used to evaluate maple syrup quality. This will benefit consumers who purchase their products.