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.

March 29th-April 6th

IMG_2915 (2)

Dr Jim Marvin (left) and Mr. Lloyd Sipple discuss an early reverse osmosis machine in Bainbridge, NY (April 20th, 1968).

While there are a few extremely cold pockets that exist, the 2016 season ended in most southerly locations over last week.  By and large, reports are that producers who have finished production had a good to very good season.  Given the cold weather that has separated periods of sap flow, some are calling this a season in three acts.  This third act (for those still producing) will begin today or tomorrow (4/6-4/7).  Depending on the quality of sap that is produced with this run, some producers will make more syrup while others will be forced to call it a season.

Bennington county reports indicate that virtually every producer is done.  However, there are at least one or two producers still going.  One operation with a higher elevation sugarbush (~2,500’) was still producing as of Sunday (4/3).  They have had a good season so far with a syrup/tap yield of 4.4 pounds.   Sap sweetness has averaged ~2.0% all season.  This is apparently a little high for their average.  No off-flavors have been made at this location.

One Addison county producer (cold location) reports average to very good sap flow on 3/30 and 3/31 respectively.  Poor sap flow is reported for the next two days (4/1-4/2).  Sap sweetness was between 1.6-1.7% at this location.  Syrup grade was either Amber or Dark with no off-flavors reported.  Lots of sugar sand was reported at this location last week.  Total season syrup production has reached 4.07 pounds/tap.

The report from Chittenden county includes one operation that has seen sap sweetness drop from 2% to 1.7% over the past week.  This operation most recently made Dark syrup with no off-flavors.  Total season syrup yield has reached 5.83 pounds/tap.  Another producer reports sap dropping in sweetness to 1.4%.  Total season production for that operation reached 6.0 pounds of syrup/tap by Saturday (4/2).  Syrup produced at that location on Friday and Saturday (4/1-4/2) changed from Golden to Amber and syrup produced on the second day appeared to have a slight change in flavor.  Other reports from around the county include producers reaching between 5-6 pounds of syrup/tap.

In Lamoille county, one producer reports a huge run on 3/29-3/31 and below average flow on 4/1-4/2.  Sap sweetness was 2.0% over this time.  Syrup produced was mostly Golden before changing to Dark at the end of the run.  No off-flavors were reported during this time.  Total syrup yield has reached 4.1 pounds/tap at this location.  Another producer reports good to very good sap flow over the past week.  Sap sweetness has ranged from 1.6-1.8%.  Syrup produced at this location was either Dark or Very Dark over the past week.  The syrup produced on 3/31 had very good maple flavor but a slight change in the flavor was also detected.  Total season syrup yield has reached 4.33 pounds/tap at this location.  In what may be true for many others, this location had sap runs large enough to equal 25% of the crop in two days.  A third producer in Lamoille county reports good sap flow over the last week.  Sap sweetness has averaged 1.8% and the syrup produced has been Amber.  Some slight change in the flavor has been detected but it is still considered table grade at this location.  Total syrup yield for this producer stands at 5.1 pounds/tap.

Orleans county (Morgan) reports good production through last Tuesday morning (3/29) but then cold temperatures and snow stopped sap flow.  Things opened up slowly on the following afternoon (3/30) and then ran hard on Thursday (3/31).  This run lasted until Sunday (4/2) and included the highest rate of sap flow and syrup production every recorded for this location.  Syrup grade was Golden.  Towards the end of the run, sap started to get cloudy and sap sweetness fell to 1.5%.  By this time, syrup grade had become Dark with good flavor.  In all, this operation reports making a mix of Golden, Amber and Dark syrup with no off flavors.  Total syrup production has reached 4.6 pounds/tap at this location.

In Caledonia county, one producer reports the sap ran between 3/31-4/2 and was ‘a season making run’.  The syrup produced early in the run was Golden and was ‘best flavored syrup of the year’.  Syrup grade darkened through the range of Amber by the end of the run.  Sap sweetness began at 2.5% and dropped progressively each day of the run, ending at 1.8-1.9% by the end.  Total syrup yield at this location has reached 4.49 pounds/tap.  This producer is taking the active step of pulling spouts on red maples before the next run.

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