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North American Maple Syrup Producers Manual, 3rd Ed.

Since 1958 the North American Maple Syrup Producers Manual has served as a basic reference source for the production of pure maple products. This 2022 edition provides up-to-date, science-based information and recommendations relating to all aspects of the industry. The guidelines presented will help users ranging from the hobby and beginning producer level to those well-established in the industry. In addition, the information herein will benefit foresters, land managers, Extension and outreach personnel, and others aiming to provide assistance to those in the maple industry. Numerous photographs, tables, a glossary and hyperlinks to selected source materials are included.

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A systems biology approach to explore the impact of maple tree dormancy release on sap variation and maple syrup quality

Maple sap is a complex nutrient matrix collected during spring to produce maple syrup. The characteristics of sap change over the production period and its composition directly impacts syrup quality. This variability could in part be attributed to changes in tree metabolism following dormancy release, but little is known about these changes in deciduous trees. Therefore, understanding the variation in sap composition associated with dormancy release could help pinpoint the causes of some defects in maple syrup. In particular, a defect known as ÒbuddyÓ, is an increasing concern for the industry. This off-flavor appears around the time of bud break, hence its name. To investigate sap variation related to bud break and the buddy defect, we monitored sap variation with respect to a dormancy release index (Sbb) and syrup quality. First, we looked at variation in amino acid content during this period. We observed a shift in amino acid relative proportions associated with dormancy release and found that most of them increase rapidly near the point of bud break, correlating with changes in syrup quality. Second, we identified biological processes that respond to variation in maple sap by performing a competition assay using the barcoded Saccharomyces cerevisiae prototroph deletion collection. This untargeted approach revealed that the organic sulfur content may be responsible for the development of the buddy off-flavor, and that dormancy release is necessary for the appearance of the defect, but other factors such as microbial activity may also be contributing.