Ask the Steward
Question: Can all maple trees be tapped for sap and syrup making?
Answer: While any of the five species of Maples native to Indiana could be tapped for syrup making it is the Sugar Maple that is most desired due to its’ higher sugar content, flavor, best yield and the longest sugaring season. Typical sap sugar content is 2-4% in sugar maple, with the less common Black maple coming in near the same as Sugar maple. Red maple is slightly less, but has a shorter season and hence less preferred from a commercial aspect- but fine for the home hobbyist. Silver maple comes in even lower at 1.5 % and its sugar sand (mineral deposits) makes it lower in desirability. Even, Box Elder, which many may not realize is a maple species, is tappable, but its’ low sugar content, small tree size and off flavor yields little interest. Maple is not the only tree species that is considered tappable. Black walnut and birch also finds favor in some regions, with birch having a long history of tapping in some regions of the world. A study at Cornell University found sugar content in Walnut sap to be roughly equivalent to that of sugar maple and the syrup flavor comparable to maple. However, sap yield from Walnut was much lower than from Sugar maple.
Believe it or not, tree sap is becoming a popular spring beverage in some areas of north America. I recall several times while working the woods in late winter and early spring finding, and tasting, icicles formed on the ends of broken maple branches where sap has dripped. You really can taste the slightly sweet flavor. If tapping for sap tasting use sterilized equipment, refrigerate the sap (it has no preservatives) and use within few days. Don’t have a maple tree and would like to sample sap water? You’re in luck. Bottled ‘maple water’ can be readily found in some groceries and on the internet.
Question: When logging why do trees skin up more easily in the spring than other periods of the year? And, how to avoid?
Answer: The answer to this question is related to the question above on tapping of maple trees. As winter fades and spring warmth comes to the forest, unseen changes begin within your trees. This includes sap flow and a surge of tree growth just under the bark in the cambium tissue. This flow of moisture and nutrients provide nourishment, which is first visually reflected in expansion of tree buds. To oversimplify, this moisture flow and growth activity just under the bark creates a soft, slippery layer which is more vulnerable to ‘barking’ or ‘skinning’ if hit by logging equipment, felled trees or skidded logs. Some species of trees are more vulnerable than others and timing of peak sap flow also varies by species.
While bark adhesion is best in late summer as sap flow slows, and through the cold of winter, if you hit a tree hard enough any time of year the bark will come off. So, what’s the answer to the active woodland owner considering a harvest? Harvests, of course, do occur throughout the year; however, regardless the season, they should be well managed and undertake at a professional level. Planning should utilize guidance from professional foresters and harvests executed by well trained, professional loggers. Written contracts are a must, and may include provisions aimed to limit residual damage, such as seasonal restrictions or excessive damage penalties. Planning a harvest? One source of good information is http://callb4ucut.com
Dan Ernst is the former Assistant State Forester for the DNR Division of Forestry and has authored this column for years; After retiring in 2019 he continues to manage forests as a woodland owner and consulting forester. Have a question for the column? Contact Dan at foresterdan@yahoo.com