April 6th-May 1st

Time to make the next generation of maple producers:  Sugar maple flowers can either be ‘perfect’ (male and female parts) or ‘imperfect’ (just one or the other) and are now thought to be mostly wind pollinated. 

The 2017 maple season in Vermont is over.  For a crop known for producing no two seasons alike, this year certainly didn’t disappoint.  Producers who were tapping during the early January sap run, had the season last nearly nine weeks.  For those who waited out the first runs of sap the season was more typical in length.  It seemed like the month of March behaved more like a cold February than anything else.  While production totals have yet to be finalized statewide, it does appear that the 2017 season was good overall.  A few producers saw yields above last year’s record crop while most operations appear to be “there or thereabouts” compared to the long term average.  It appears that syrup flavor was excellent for most producers, with only limited reports of off-flavors received.

A Bennington County producer reports the season ended on April 3rd.  This operation began tapping in early February and first boiled on February 19th.  The sap sweetness was noticeably low this year (averaging ~1.5% for the season).  The last boil was on April 13th.  Total yield for this operation was 0.172 gallons of syrup/tap (1.9 pounds/tap).  This is estimated to be about 85% of an average crop for this producer.  Syrup grade was almost all Dark-Robust.  No off-flavors were reported.

A Windsor County producer reports a record year, eclipsing even last year’s totals.   The boiling season began on February 22nd and lasted until April 11th at this location.  Good runs of sap were reported on 8-10th of April.  The crop included some of all four grades of syrup.  No off-flavors were detected.  Syrup yield from this operation reached 0.62 gallons of syrup/tap (6.82 pounds/tap) in 2017.

An Addison County producer reports having the second best season on record.  Syrup grade ranged from a light Amber-Rich to Dark-Robust.  No off-flavors were detected.  This relatively cold location began tapping on February 8th, finished tapping on the 19th and had their first boil on February 23rd.  Good runs of sap were seen up until the end of the season.  Syrup yield reached 0.46 pounds of syrup/tap (5.08 pounds/tap) at this location.

One Lamoille County producer in a relatively cold location saw better than average production this season.  The sap sweetness averaged over 2% for all but the final week of the season.  This operation was still in the process of tapping when a big run came in mid-February.  Syrup grade was consistently light with ‘Golden or very light Amber comprising about 2/3 of the crop’.  As with others around the state March was colder than average.  This operation only boiled 6 times in March but made up for it with good April sap flow.  Total production at this location reached .44 gallons of syrup/tap (4.8 pounds/tap).  Another Lamoille County producer reports a good season that started after the first big run in February.  Good vacuum made up for lost time, average vacuum levels were around 24” Hg.  Syrup grade weighted towards Amber (80%) and a small about of Dark and Very Dark made at the end of the season (11% and 9% respectively).  Sap sweetness averaged about 2% during the season and dropped to below 2% at the end.  Total yield at this location reached 0.33 gallons of syrup/tap (3.6 pounds/tap).

An Orleans County producer reports finishing up production on April 13th when syrup took on a slight Buddy smell.  Unusual for this location was that >90% of the crop was very light Amber or Golden.  The last week of production saw average sap flow.  Sap sweetness had dropped to 1.7% and Dark-Robust syrup being produced.  Total yield for this operation reached .43 gallons of syrup/tap (4.7 pounds/tap).

Many thanks to all the producers who took time from their busiest time of the year to gather and contribute weekly data for this project.  Many operations appreciate hearing how the season is progressing around the state and you make this possible.  Thanks!


March 18th-April 5th

Neighbors boiling:  Steam rises from two sugarhouses along the Lamoille River valley while just out of view, two more operations work through a batch of syrup.

The 2017 season continues across the state.  While southern or traditionaly warmer areas are finishing up, some of the cold locations are just hitting their stride.  While it’s too early to tell how the crop will turn out statewide, it’s clear that the early start to the did not significantly limit overall yields for most producers.  Reports of excellent syrup flavor and some locations with above average sap sweetness have been received.  Snow remains in the woods across the northeast of the State and will likely allow the season to continue for at least another 1-2 weeks.   Forecasted temperatures reaching the 70’s for early next week will bring the end for many operations.

In Bennington County the season is nearing an end.  One producer reports average sap flow over the past week.  The night of 4/2 might be the last freeze of the season.  Sap has averaged 1.7% over the last week.  Dark/Robust syrup is being made at this location with no off-flavors reported.  Total syrup yield at this operation has reached 85% of an average crop.  Some reports of taps shutting down have come in and at least one observation of spring peepers singing on 4/3 makes it seem like all but the coldest areas in the county will be done by the end of the week.

One Rutland County producer reports boiling for a seven-day stretch (3/28-4/3).  Temperatures below freezing each night and ‘just the last couple of days above 45.’.  Syrup made has been a very light Amber/Rich (‘so close to Golden’) with very little Dark produced and no off-flavors.  Abundant (‘more than I have ever seen in my sugaring lifetime’), very light colored (‘snow white’) sugar sand built up like ‘sand dunes’ in the syrup pan.  Sap sweetness had been holding at 2% but has dropped to 1.8% recently.  This operation estimates the yield to be around 3.6 pounds of syrup/tap or roughly 85-90% of an average crop by the end of 4/3.

In Windsor County a producer reports a great run beginning on the afternoon of 4/1 and continuing into 4/2.  The following day 4/3 has a slower run.  Sap sweetness has averaged 2.0% at this location over this period.  Amber/Rich syrup with no off-flavors has been produced.  Total yield has reached 4.8 pounds of syrup/tap which is estimated to be 110% of an average crop.

In Washington County a producer reports that sap flow has been very good over the past week.  Sap sweetness has averaged 2.0% during this time.  Amber/Rich syrup with excellent flavor has been produced.  Total yield has reached 1.87 pounds of syrup/tap.  According to this producer, the relatively low production numbers are likely a result of not capturing all of the sap runs in February.

In Addison County a producer reports good sap flow coming 4/1-4/2.  The sap sweetness was 2.3% during this time.  Syrup grade has been Amber/Rich (some of which was very light in color).  Sugar sand returned and the syrup was the ‘best tasting of the season’.  Another hard run of sap on 4/3 saw sap sweetness go up slightly (2.4%) and very light colored Amber/Rich syrup with great flavor being produced.  So far at this (usually cold) location the total syrup yield has reached 80-85% of an average crop.

In Lamoille County a producer in a cold area reports that sap has ‘finally started to flow…”.  Sap flow over the last week has been average but ‘poor for the season’.  This operation reports measuring sap sweetness between ‘2.8-3.2 for 5 days.’ Sap has not been below 2.0% all season.  Syrup grade has been mostly Amber/Rich until recently when the color turned to Golden with lots of niter.  The syrup flavor has been ‘the best Golden we’ve ever tasted’.  Total syrup yield has reached 2.7 pounds/tap at this location.  This represents about 50% of an average crop for this operation.  Besides the 1st barrel of the season, none of the crop has been off-flavored.  Another producer in Lamoille County also reports sweet sap (averaging 2.5% sugar).  Sap flow has been average over the past week.  Syrup grade has been Golden/Delicate with no off-flavors.  This operation has reached 3.9 pounds of syrup/tap which represents about 2/3’s of an average crop for this location.  Based on the current forecast this producer expects to be able to boil for another week and a half to two weeks.

In Orleans County on operation reports very good sap flow over the last period.  Six inches of wet snow fell on April 1st that ‘resulted in our sweetest and largest sap runs for the season’.  Syrup grade was Golden on 4/2 ‘which is unusual for our sugarbush.’.  Sap sweetness has averaged 2.2%.  No off-flavors have been detected.  Total syrup yield has reached 2.2 lbs/tap for this producer.  This represents about 50% of an average crop.

In Essex County a producer reports that sap ‘finally started running last weekend (3/25-3/26) but it too 2 days to get enough sap to boil.’.  This operation boiled each day from 3/28-4/2 having previously only boiled on 3/9 and 3/22.  By 3/22 this operation was at about 25% of an average crop.  Sap in March averaged 2.0-2.2% sugar and syrup was Amber/Rich or Dark/Robust.  The sap collected in April has averaged 2.6-2.8% sugar and the syrup grade has been Amber to just below Golden/Delicate in color.  This operation has now reached about 45% of an average crop.  As of 4/3 there was still 2’ of snow in the woods and no tree wells appearing around the bases of the trees.

March 4th-March 17th

Waiting for warmer weather:  Roadside buckets in Caledonia County sit idle until the next run of 2017 sap. 

Vermont’s 2017 sugaring season is currently in a holding pattern due to cold temperatures and heavy snow that fell over the past week.  The prevailing story before this cold period was how early the season began at many locations and shear length of time with above average temperatures.  The past 8 days have seen below average temperatures and near record snowfall.  It has been said that “an average is made of many numbers” sometimes the numbers that make the average are close together and sometimes they are all over the place.  If the 2017 season in Vermont turns out to be ‘about average’, it will likely get there more like the latter.

The long period of above average temperatures had many asking about an early onset of spring and maple bud break.  As mentioned in the previous Bulletin, the scientific study of climate and periodic cycles in nature is called phenology.  The observation of spring bud development in maples is a form of phenology.  The process whereby a given tree begins to exit dormancy is complicated, stimulated in large part by the accumulation of warm days.  Growing Degree Days (GDD) is one measure that averages daily high and low temperature and subtracts it from an accepted base value.  The base value can be different for different species (for maple, 32F is often used).  Not all species will break bud at the same time since different species have different strategies related to spring activity and therefore have different requirements for accumulated GDD.  The map below helps illustrate how parts of the maple world (more southern areas) have seen a very early end to the season whereas other parts (more northerly parts such as Vermont) continue to produce.

A tale of two maple seasons:  A map depicting the accumulated Growing Degree Days (GDD) as of March 16th, 2017 shows how much closer southern maple producing states are to spring than northern parts.

Spring tree phenology is more complex than accumulated GDD alone but it does help tell the story.

In Bennington County one producer reports poor sap flow over the last period.  Sap sweetness was averaging 1.7 brix.  Syrup produced was Very Dark/Strong Taste with no apparent off-flavors.  Total yield at this location has reached 0.8 pounds/tap which represents about 35% of an average crop.


In Washington County a producer reports very good sap flow over the last period.  The sap averaged 1.7 brix.  Syrup produced has been Amber or Dark in grade with no off-flavors detected.  Total yield has reached 0.93 pounds of syrup/tap.


A Windsor County producer reports very good flow of sap between 3/7-3/9.  Sap sweetness averaged 1.8% at this location.  Syrup produced was Amber with no off-flavors.  Total yield at this location is now at 3.0 pounds/tap.  This represents about 66% of an average crop for this operation.  It sounds like others around the county have reached about 50% of an average crop.

One Lamoille County producer reports very good sap runs over the last period.  Sap averaged 2.0% during this time.  Syrup produced has been Amber with no off-flavor.  Another producer reports making good flavored Amber (then lightening to Golden) syrup.  Sap sweetness has been between 2.0-2.2% at this location.  The total syrup yield is around 20% of an average crop.


In Orleans County a producer reports average sap flow over the last period.  Sap sweetness was averaging 1.8% during this time.  Syrup grade was Amber with no off-flavors reported.  Total yield at this location was 1.1 pounds/tap.  This represents 20% of an average crop.

February 22nd-March 3rd

A mess of green tubing:  Lateral lines at the University of Vermont Proctor Maple Research Center lead to experimental chambers do not follow a typical tubing layout. 

Syrup production reached all parts of the state over the past week.  In general, producers who either by necessity (large operations) or choice (desire to catch early runs) were tapped and have reported a good season so far.  Some operations reported being a little behind during the prolonged period of unseasonably warm weather.  Some reports of mild to strong metabolism off-flavor have been received.  There have been a few reports (including one from Lamoille County below) of excessive mineral buildup on RO membranes.

Tree phenology is the study of seasonal and cyclical patterns of trees development.  Spring bud break is one of these patterns.  Unusually cold spring weather can delay bud-break whereas warm spring weather can accelerate the spring development of dormant sugar maple buds.  A long term set of observations (1991-present) and summary for sugar maple by the Vermont Monitoring Cooperative can be found here:  http://www.uvm.edu/vmc/about/annual_report/2014/phenology

One producer from Bennington County reports boiling 2/19, 2/22, 2/23, 2/27 & 2/28.  The sap sweetness at this operation is reported to be low (1.5-1.7%).  Syrup produced has been Dark Robust.    This producer has reached approximately 20-25% of a regular crop at this location.  Other reports from Bennington County indicate similarly low sap sweetness and dark grades of syrup being produced.  It appears that producers who were tapped in January (some for the first time) were well positioned to catch sap runs in early February ‘did well’.

A Windsor County producer reports tapping was completed between 2/20-2/23 (in record time).  Very strong runs came during last week and again beginning the afternoon of 2/27.  As of 2/25 this operation was at about ¼ of an average crop and by 3/3 this yield had reached approximately ½ of an average crop.  This producer reports never having made ‘this much syrup this early’.  A little less than ½ of the syrup is Golden with excellent flavor with the balance being Amber.  The sap sugar content at this location began around 2% and has since dropped to an average of 1.6-1.7% by the ‘end ‘of the run.

Some sap flow experiments at University of Vermont, Proctor Maple Research Center are more complicated than others:  From 1964, ‘tree cut, space between trunck and stump dammed with plastic material, trunk put back in place.  Flow from trunk and stump recorded separately’.  J.W. Marvin, F.M. Laing, Claude Wagner and Floyd McLellan.   

A Rutland County producer reported tapping began on February 18th.  As of 2/27 tapping was nearly complete.  Good sap flow resulted in full tanks on 2/22.  First boil was on 2/23 with ‘nice Golden’ syrup having been produced.  Air temperatures reached 70F at this location on 2/25.  Sap continues to run with good vacuum (27” Hg) at this location despite a lack of cold temperatures.  This producer reports ‘all our snow has turned to mud’ during this period.

An Addison county producer with a relatively cold, northwest facing sugarbush reported finished tapping on February 19th.  First boil at this location was 2/23, with sap sweetness reported as 2.1% and very light Amber syrup (just below Golden in color) with excellent flavor being produced.  Boiling on the next two days (2/24-2/25) produced more good flavored Amber syrup with 2% sap sweetness on average.  A hard run of sap was reported on 2/28 at this location and sap sweetness holding at 2%.  Good flavored Amber syrup continued to be made.  Another strong run of sap into 3/1.  Sap sweetness has remained steady at 2% for this producer.  Good flavored Amber syrup continues to be produced at this location.  No off-flavors have been detected.  Total production at this location has reached approximately 1.6 pounds/tap.  This represents more than 1/3 of a crop for this operation.

A Washington County producer reports boiling two times by 2/27.  Sap averaged 1.8% and syrup grade was Amber with no off-flavors reported.  Tapping was 85% complete by this point.  Only patches of snow remained at this location (1200’ elevation).  3/1 brought this operation’s total yield to 0.5 pounds/tap.

One Lamoille County producer was 95% tapped as of 2/28.  First boil was 2/23 with another on 2/25.  First syrup produced at this location had a ‘very mild metabolized flavor’.  The off-flavor did not persist and all other syrup ‘has been fantastic flavor’.  Syrup grade has been Amber with color trended lighter with each barrel over this period.  This cold location still had plenty of snow on 2/28.  Sap did not flow well on 2/27.  A second Lamoille County operation reported very strong sap flow for the week 2/18-2/24. Sap sweetness 2.4% over this period.  This sap produced Golden syrup with no apparent off-flavor.  Yield was reported at 1.0 pounds/tap at this point with no off-flavors were detected.  As of 2/27 this operation had reached 1.28 pounds of syrup/tap (not quite ¼ of an average crop for this operation) Sap sweetness ranged from 2.0-2.5 over the five days 2/23-2/27.  This producer reports heavy mineral buildup on new RO membranes after only ‘just a little sap’ had been processed.  This producer was able to get flows back after acid washing.  The warm weather on 2/25 turned sap cloudy at this location.  Sap was clogging RO prefilters ‘just like it does in late season’.  Tapping was +95% completed as of 2/27 and expected to be finished by the end of the week.  As of 3/2 this operations syrup yield has reached 1.89 pounds/tap.  Very good sap flow averaging 2.3%.  ‘Very strong metabolism’ off-flavor was detected starting with syrup made on 3/2.  This operation boils sap from two locations and it was attempting to determine if one of the sources contributed to the off-flavor more than the other.

An Orleans County producer with roughly 3000 taps reports tapping began 2/19.  Deep snow (+3’) was estimated in the woods.  Sap was collected 2/23-2/25 and tested at 1.8%.  Boiling on 2/24 and 2/25 produced Amber syrup with no off-flavors reported.  A fresh coat of snow (6”) feel on 2/25.  Sap was running 3/1 at this location.  Tapping was expected to be finished on 3/2.

In Essex County, a producer reports tapping finished on 2/28.  First boil was on 2/24.  Sap sweetness was 1.7 and produced Dark syrup.  Sap was 2% on both 2/25 and 3/1.  Syrup was Dark on 2/25 and Amber on 3/1.  By this point, yields at this location had reached approximately 10% of a crop.  Syrup quality was ‘all nice’ and ‘no sand or nitre’ was reported.


Vermont Maple Bulletin 2017

The 2017 Vermont maple syrup production season has begun and with that comes the second year of the Vermont Maple Bulletin.  The Bulletin is an attempt to capture the week to week flavor of the maple season throughout the state.  The Bulletin is not intended to be rigorous analysis but rather a brief summary of the action during the season.  The first post of 2017 will be a somewhat abbreviated one as this is still the cusp of the season.  Many operations in Vermont have some made syrup as of today (2/21) but many more are still ramping up for the season.  Expect more detailed posts as more reports come in.  The next seven days have the potential for good runs of sap.

First a look back in time.  The beginning of the season came for some during the brief but significant warm period in January many more producers choose to wait out the January thaw.  The warm temperatures were fairly uniform across the state even some of the coldest pockets (see below).



Responses from producers could generally be described as saying “it’s still too early to tap”.   Of course it won’t be until the end of the season that it will be known if going early was a good strategy.  Those operations that had begun tapping out of necessity (very large operations) or those that were especially interested in capturing early sap did make some syrup.  Generally, the total syrup produced from these runs of sap accounted for roughly 5% of operations total average crop. At least one operation reported reaching 10% of an average crop during this time.

A January report from much further south (Litchfield, Connecticut), had an operation at 1200 feet elevation tapped on 1/26-1/27, collected 400 gallons on 1/28 and boiled on 1/29.  With average sap flow rates that producer saw sap sweetness at 2.0%.  Syrup grade was Dark at this time with no off-flavors.  Total yield had reached just under 0.2 pounds/tap as of 2/4. One large producer in Lamoille County reported collecting sap from just over 13,000 taps during the warmth of the second week of January.  Sap sweetness was reported to range from 1.6-2.3%.  As of January 27th this producer had seen average sap flow rates, made Golden syrup with no off-flavors and accumulated 0.5 pounds of production/tap.

Tree wells (the name given to when snow melts away from the base of a tree) are a good indication that sap flow is possible.  Sap flow in smaller trees tends to be more responsive to warming events but will generally produce proportionally less volume.  

A few scattered reports from around the state indicate seasonable sap sugar contents to good mid-season sugar contents.  It is hard to characterize this period without a larger number of reports.  Syrup quality appears to be good and some accounts of very good sap flow rates might be an sign that trees are not deeply frozen as can sometimes be the case this time of year.

Stay tuned for the next update.


April 13th-April 21st

Get while the getting is good:  Small sugar maple trees growing in the understory, such as the one pictured, leaf out early in order to make more than 75% of their yearly carbohydrate production in the days before the overstory fully leafs out.  

The 2016 season ended for virtually all operations in Vermont this past week.  While some operations were not pleased with this year’s production, many have had an average to above average crop of syrup.  Operations from all parts of the state have reported seeing a few runs of sap greater than anything seen in recent history.  Some of these operations report making 10-20% of their entire crop in 24 hours.  While early warm temperatures allowed producers to make syrup in late January-early February it’s not yet clear how much these early runs contributed to the total yield.  A lack of many reports of widespread off flavor suggest that this year was good in terms of flavor.  The story of sap sweetness 2016 also remains unsettled.  There have been many reports of below average sap sweetness while other producers report average to above average sweetness this year.  Without detailed records and standardized methods of when and how to measure sugar content it is difficult to draw too many conclusions on this subject.  No doubt this will be vigorously debated in the months to come.

In Addison county, a producer reports that 4/19 was their last boil.  This producer reports an above average season.  The season began at this cold location on 3/9.  The sap sweetness averaged 1.5% during the last week.  The syrup produced was Dark with no off flavors reported.  Total season syrup production reached 4.47 pounds/tap at this location.  There was a ‘monster run’ on 3/12 at this location (larger than anything seen in eight years and represented ~7.5% of the entire crop).

In Rutland county, one operation reports that the season ended on 3/31 and production was average overall.  Season syrup yield was 4.2 pounds/tap.  This operation saw weather as the greatest challenge to having a more productive season.  Early warm temperatures and a few noteworthy high temperature days may have impacted late season sap flow by enhancing microbial growth in tap holes earlier than normal.  The syrup produced at this location also appeared to reflect the periods of above average temperatures with some good flavored Dark syrup being made in mid-March.   This operation saw very little in the way of sugar sand.  This producer noticed that during part of the season, the niter took on a dark, cloudy consistency even while Amber syrup was being produced.  At the end of the season, following ‘the last cold spell’, abundant white sugar sand was developing faster than normal.

Operations in Chittenden county have reached the end of the season as well.  One producer reports an above average crop.  Sap sweetness was down to around 1.5% at the end.  The total season production was 6.75 pounds of syrup/tap at this location.  This represents a little above the 12-year historical average for this location.  This producer chose to dump sap a few times late in the season to keep syrup quality from dropping to Processing grade.  Another producer reports ending the season on 4/16 and reaching 7 pounds of syrup/tap.  Syrup grade was a mix of Golden and Amber mostly.  Not much off flavored syrup was reported at this location.

In Lamoille county one producer reports being very pleased with the season.  This operation first made syrup on February 29th and the last boil of ‘decent syrup’ was March 31st.  A boil on March 11th produced severely buddy syrup.  March ended up being a very productive month, with some the greatest sap flow occurring between the 25th-27th.  The sap sweetness was perhaps lower than normal at this location.  This producer reports sap starting out at 2.0%, dropping to and remaining at 1.8% for most of the season.  The last run of sap was 1.6%.  Syrup grade tended to be darker than average for this producer.  Except for a few gallons of borderline Amber/Rich at the start of the season, 2/3 of the syrup was Dark/Robust with the remaining 1/3 coming in at Very Dark/Strong.  The bulk of the crop was Total season syrup production at this location was 4.34 pounds/tap.  Another producer reports that the season has ended (4/19).  The sap flow over the past week was good in general and slowed down following the last warm up.  Sap sweetness dropped from 2% to just under 1.8%.  Syrup was mostly Amber/Rich but changed to Dark/Strong with no off flavors on 4/17.  Total season syrup production at this location has reached 5/5 pounds/tap.  This represents the ‘best season by far for our three years (in operation)’.  This producer attributes the high production to two factors; length of season and sweeter than average sap.  This producer also reports making at least 15% of the crop as off flavored syrup in the previous two years.  This season it is unlikely that any of their crop will be off flavored.  Yet another operation reports that the season continued as of 4/18.  The past week saw average sap flows and sap sweetness around 1.7%.  The syrup produced had ‘decent flavor’ for most of the week until late Sunday when things changed dramatically.  Sap flow ‘dropped way off’ and flavor was no longer table grade.  Total season syrup production reached 6.25 pounds/tap at this operation.

The past week brought light, good tasting syrup as well as the end of the season to one operation in far eastern Orleans county.  The final boil at this location was on 4/18 with Dark syrup being produced.  Total season syrup production reached 6.2 pounds/tap for this operation.  This a ‘very big year’ for this operation, exceeding past records for production/tap dating back more than 35 years.

In Caledonia county a producer reports the end of the season arrived on 4/17 with the onset of buddy flavored syrup.  The sap sweetness was still running 1.5-1.6% at the end.  This producer also reports that sap sweetness was above average this year without a lot of niter ‘and barely any sugar sand’.  The total syrup production at this location ended up at 6.3 pounds/tap.  The season lasted from 2/25-4/17 at this location with 19 days boiled.

In Essex county, a producer expected the end of the season to be on 4/19 as the sap had turned buddy on 4/18 and sap flow was quite slow.  Sap sweetness dropped from 1.7% to 1.5% over those two days.  This operation saw its first run of sap on 2/2.  The majority of the syrup produced at this location was Golden and Amber.  There was not much Dark syrup made.  Total season syrup yield was just under 4.25 pounds/tap.  This producer reports the best week of production came between 3/27-4/2 with extremely large runs of sap.


A wood pellet evaporator in operation earlier in the season (Hyde Park, VT). 

Lastly, this will be the last edition for the 2016 season.  A tremendous thank you to all the producers who took time away from their operations to contribute information for this project.  With very little advertising or promotion, the Vermont Maple Bulletin has received a good deal of attention and positive feedback.  The Bulletin will be continued next season.

Mark Isselhardt

University of Vermont Extension Maple Program

April 7th-April 12th


Syrup production continues on at Thunder Basin Maple Works in Cambridge while snow continues to cover the summit of Mount Mansfield in the background.

The end of the season has come for more operations this past week.  The sunny skies and the warmest temperatures seen in quite some time will likely halt production by this weekend for many operations.  Across the board, the reports are of a good to great season.  Many producers report gathering sap during the early warm weather.  Even those who did not collect early appear to be on track for a good crop.  Operations in the northern third of the state continue to collect sap, with especially cool pockets reporting clear sap and good quality syrup being produced.

The sense from around Bennington county is that most producers had a great production season.  It also appears as though less Golden syrup was produced this year.  One producer with a higher elevation sugarbush (~2,500’) reports boiling twice last week with the syrup taking on a slight metabolism off flavor following a period of cold weather.  The off flavor was no longer present on Tuesday (4/12) when more syrup was produced.  Sap flow at this location was generally poor over the past week.  Sap sweetness averaged 1.9%.  Syrup produced was Dark or Very Dark during this period.  Another producer reports a season long syrup yield reaching 4.04 pounds/tap so far. Some operations are reporting below average sap sweetness while others are not.

In Windham county a producer reports that production is continuing for a while longer.  They will likely end production this week as warm weather returns.  So far the season long production stands at just over 5.5 pounds of syrup/tap.  Some of that production was from buckets.  The bucket only production was just under 3 pounds of syrup/tap.  Peepers were heard at this location on Wednesday (4/13).

In Washington county, one producer reports boiling last Friday (4/8) for the first time in a week.  The syrup had ‘end of season taste, color and smell.  Syrup didn’t filter well either’.  The total syrup yield at this location has reached just under 3.4 pounds/tap.  This operation plans to keep going until buddy syrup is produced.

In Addison county, one producer reports below average sap flow over the past week.  The sap sweetness has dropped to 1.5%.  Dark syrup was produced with no off flavors and very little sugar sand.  Total syrup yield at this location has reached 4.13 pounds/tap.

In Chittenden county, one location reports reaching 6.8 pounds of syrup/tap.  Syrup grade is Amber to Dark with some off flavor.  Another location reports sap sweetness has dropped to 1.5-1.6%.  Total season yield has reached just under 6.6 pounds of syrup/tap.  Late season syrup flavor (perhaps a light buddy) is being reported.


Vacuum sap collection chamber at UVM Proctor Maple Research Center.  These chambers are part of an ongoing, long-term project investigating sugar maple (Acer saccharum) stem growth response to two levels of sap extraction (high vacuum and gravity) compared to control (no extraction).  2016 was the third year of this project.

In Lamoille county, one producer that finished on March 31st reports that sap sweetness appeared to be lower than normal for that location.  3-4 early sap runs averaged 2-2.2% at most.  Everything since then has been below 2.0%, with last week’s sap testing at 1.4-1.5%.  This operation has made all Dark or Very Dark syrup.  Another sugar maker reports very little sap this past week.  A short run on Thursday afternoon and Friday morning (4/7-4/8).  Sap sweetness was 2.0% or just below.  Syrup grade has been Amber to Very Dark with no off flavors this past week.  Total syrup yield at this location has reached 4.25 pounds/tap.  One more producer in Lamoille county reports generally good sap flow over the past week.  The sap sweetness at this location averaged 1.7% over this period.  Syrup being produced is now Amber with some light buddy off flavor.  The overall sense around Lamoille county is that it has been and excellent production year.  Some say it has been the best year ever (although changes and improvements to the tubing systems may account for some of the added production).

The season continues in Orleans county where one producer reports good sap flow last week (4/7-4/8) until the cold weekend weather shut everything down.  Sap sweetness was 1.6% over this time.  Syrup produced was Dark with no off flavors reported.  A run on Monday (4/11) saw sap sweetness climb up to 1.8% and syrup grade lighten to Amber.  New sap is reported to be clear.Total season syrup yield has now reached 5.0 pounds/tap at this location.

In Caledonia county one producer reports that sap sweetness has been high this year.  This operation has only collected sap below 2.0% for 6-8 hours all season.  The last test of sap was 2.2%.  The syrup was a ‘great tasting Amber/Rich’ that the sugar maker was convinced would be commercial.  This producer thinks they will be able to continue through this week but expects the sunny weekend weather will negatively impact syrup flavor.  Total syrup yield has reached 4.89 pounds/tap at this location.