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News
By Vicki Browne
From the last week of January through the first week of February when daytime temperatures hit the 40’s and nighttime temperatures dropped below freezing, Ken Willis gathered over 7000 gallons of sap or ‘maple water’ from 5500 taps on the Willis Family Maple farm.
“In the six years we’ve been here, this is the earliest we’ve ever tapped,” said Willis during a phone conversation with the Reporter.
According to an article by Russell Kidd, an educator with Michigan State University Extension, maple syrup producers in the Upper Peninsula don’t traditionally start tapping trees until mid-to late-March. The Michigan Maple Syrup Association’ s Maple Weekend for 2024 in the U.P. isn’t until April 6-7. The sap is definitely running early this year.
This is an El Nino year which means warmer temperatures in the Pacific Ocean raise humidity levels which affect the jet stream off the west coast according to Eric Baerren’s online interview with Zachary Johnson, a professor in Central Michigan University’s Department of Earth and Atmospheric Sciences. This leads to a warmer, drier and milder winter in Michigan.
We also experienced a stretch of dangerously cold temperatures in January produced by distortions in the stratospheric polar vortex. The polar jet stream dipped southward and there were record low temperatures from Montana to Texas according to Matthew Barlow , a professor of climate science at UMass Lowell.
Looking at the certified snow totals for the last two winters, we have had only 34 snow events, many just trace amounts, whereas the prior winter had 42 events through February 10, several of which were multi-day and yielded significant snowfall. The Extreme Weather website lists 2024 unofficially as the least snowy winter for Iron River in 129 years of recordkeeping.
Nancy Bergeron and Roger Sedjo looked at the effects of an El Nino winter on the maple syrup industry in a paper published in June 1999 for MIT. They noted that a midwinter freeze and thaw can result in an early harvest or even two harvests, but can also weaken the trees. Ice storms associated with El Nino years can damage trees, and warmer winters may shorten the sap-gathering season. Although not associated specifically with El Nino, winters with little snow can lead to frozen roots, potentially resulting in die back where outer branches in the tree canopy die.
Bergeron and Sedjo also noted several interesting facts about maple syrup production:
• In 1634 Father Paul Lejuene wrote about indigenous people’s springtime maple sap gathering rituals. This is perhaps the first written record of this practice.
• Maple sap is only gathered in northeast North America and only from three types of maple trees –sugar, red and silver.
• Canada produces about 75% of the maple syrup sold and the U.S. produces about 25%.
• Maple trees have a unique physiology in which wood fibers are filled with gas which contracts as temperatures decrease, rather than water which expands. This means sap is drawn up from the tree’s roots when it’s cold, freezes overnight and then flows back down as the day warms.
• The more sucrose in the sap, the better the syrup. Early sap has more sucrose while late sap has more fructose and glucose.
• The best conditions for a good maple sap harvest include a warm and sunny summer followed by a fall where the ground freezes before the snow accumulates, a long stretch where the ground is frozen and abundant sunshine on harvest days so the tree’s bark warms.
Willis indicated that they were able to take advantage of the early harvest because they run a tubing and vacuum system, rather than a bucket system. They are also able to handle large volumes of maple water because they use reverse osmosis to take the maple water from 2% sugar to 15% sugar before boiling and evaporating water out to turn the sap into syrup.
In a tubing and vacuum system each section of tapped trees are connected to a collection container using tubing. The vacuum uses gravity and pumps to ensure there is lower pressure in the tubing than in the tree. This system can double or triple a maple syrup farmer’s collection rate.
Reverse osmosis squeezes water out of the sap by passing it through a membrane. The sugars in the water are too big to fit through the membrane, so their concentration in the collected sap rises. This also reduces the boiling time to get the sap to 66.5% sugar, the usual concentration for maple syrup.
“Reverse osmosis means better fuel economy – more miles per gallon, so to speak,” said Willis.
He is hoping to get this batch boiled before temperatures return to our usual winter weather.
Based on the 40:1 ratio of sap to syrup, we can expect to find 175 gallons which equals 1400 16-ounce bottles of Willis Maple Farm syrup on store shelves soon!