A Funny Thing Happened to My Sap on the Way to the Evaporator

The following article was written and published in The Maple News May edition. In the article I took  a look back at the 2017 maple season. In Ohio it was very different and in many ways very educational.

The 2017 syrup season saw Mother Nature throwing just about everything at Ohio maple producers. In years where everything seems to go as planned, and production is good, we tend to overlook what can happen when we have deal with extreme conditions.  2017 was a year of extremes; we were constantly exposed to either extended warm or cold weather. The season started early for many and never really got off the ground for others.  February 20th was the beginning of a warm spell that ended on February 24th with the temperature in Cleveland, Ohio reaching 77 degrees, breaking several records in the process. The first two weeks of March were cold with minimal sap flow; this was followed by a warm up that ended the season on March 27. After a year like 2017 many Ohio producers are still wondering what actually ended the season.

When sap comes from the tree, the sweet liquid is sterile. Once the sap is exposed to the environment colonies of bacteria begin to grow in the liquid. A 2003 research study done in Quebec, Canada by Legace, Pitre, Jacques and Roy isolated 32 different t isolate groups of bacteria found in maple sap. As producers we often think of bacterial growth as bad because many of these bacterial strains cause maple sap to spoil (Morselli and Whalen 1991 & 1996). The ironic fact is that not all bacteria are bad and several strains of bacteria and yeasts are needed to give maple syrup its unique flavor and color (Wilits and Underwood). This was reconfirmed in a 2011 study done in Quebec Canada by Filteau, Legace, Lapointe and Roy. The Maple syrup is almost 100% made up of the sugar known as Sucrose. When bacteria are introduced into the sweet sap solution fermentation occurs via hydrolysis that results in the breakdown of a small percentage of the sucrose into fructose and glucose. This is often referred to as the invert portion of the maple sugar complex. When heat is introduced, there is a thermal reaction (Millard Reaction) that causes the browning of the liquid during the boiling process. This gives maple syrup its signature amber color and unique flavor.  As the bacterial contamination increases the result is an intense darkening of the syrup and a pronounced strong flavor. With an overabundance of bacterial growth in the sap results in the formation of acids that can cause a sour smell and taste known as Sour Sap. If boiled into syrup, the syrup often becomes thick and stringy, forming Ropey Syrup.  The highest probability of this type of contamination usually occurs at the end of the season.   However, as many producers found out this year,   it can happen anytime during the season, when environmental conditions are right and bacterial growth is left uncontrolled.

As we reach the end of a season, one of the most often asked questions is; how can I tell when the season is over. During a normal season we have two completely different biological processes that often occur simultaneously at the end of the season.  This can be confusing to producers especially new producers.  The season ultimately comes to an end when the trees begin bud formation and leaf emergence. The presence of abnormal sour sap is often mistakenly associated with the budding process because in a normal season the onset of warm weather not only increases bacterial growth but is pushing the trees closer to the formation of buds.  The off flavor associated with budding is similar but distinctly different than Sour Sap. Buddy Syrup has a chocolate or tootsie roll like flavor and when boiled, the steam will take on an unforgettable pungent aroma. The easiest way to identify buddy syrup is to boil a pot of the suspected liquid on the stove and wait for the aroma. If the aroma shows up the season is over.

February 24th marked the end of the season for many Ohio producers despite the onset of cold weather in the first half of March. Those that tap predominantly Red Maple were justified in their decision based on the premature bloom of their trees. Others simply lost the battle to bacterial contamination. The producers with the best chances of extending the season past the freeze up were those using tubing systems that were run continuously 24/7, regardless of sap flow during the warmup. Continuous operation keeps the sap flowing away from the tap hole and it also has a cooling effect, as a result of air being transferred through the lines. In addition almost all were using some type of tap hole sanitation technology in the form of check valves or regular replacement of spouts and drops. The key word here is sanitation. Producing top quality syrup starts with a tubing system and equipment that is properly cleaned and stored at the end of the previous season.  It continues with constant sanitation of equipment throughout the maple production process.  A good example is replacing plastic sap storage tanks with easy to clean stainless steel tanks. Plastic tanks are one of the worst harbingers of bacteria because the plastic is porous and cannot be easily cleaned or sanitized. Many of the larger operations have now adopted new evaporator cleaning systems that clean not only the front pans but also the flue pan. This involves draining the back pan between runs and recirculating RO permeate water to remove niter and slow bacterial growth in the evaporator.  Cleaning your equipment immediately and processing your syrup as quick as possible is essential if you want to make a quality product throughout the season.

We can control sanitation and processing but the trees are a different matter. Can a maple tree rebound after warm weather and a long shutdown? There is no definitive answer to this question. Each sugar bush has its own characteristics and will respond differently to environmental conditions.    The reality is, you can make a good season better by extending the season, but you cannot make up for the production you have lost as a result of not tapping on time. Across the state Ohio producers were tapping in January, 3 out of the last 5 years.  Only in 2014 and 2015, the years of the Polar Vortex, was tapping delayed into late February and early March. You can never duplicate the flow of a fresh tap precisely placed at the start of the season. Many of those producers tapping early in 2017 learned this lesson the hard way in 2016. As a result those that tapped early in 2017 had an average to above average seasons all because they were able to take advantage of the opportunity.

Late season runs are often marked by diminishing returns, yet some producer pride themselves on the fact that they can make syrup long after everyone else is done. The question is, what are they making and where will it end up. Ultimately the quality of the product has to be the deciding factor in knowing when to end the season. Attempts to make commercial syrup at the end of the season are usually a waste of the producer’s time and money. Sacrificing quality for quantity only results in a surplus of low quality syrup that should never reach the market place.  Unfortunately many times this syrup goes into the marketing pipeline, ending up on a store shelf, headed for the table of an unsuspecting   consumer.  This type of production and marketing practice has no place in the maple syrup Industry.

Les Ober Geauga County OSU Extension

Advertisements

Leave a comment

Filed under Maple Syrup in Ohio, Maple Syrup Quaity, Syrup Producing Weather, Taphole Sanitation

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s