Maple Syrup – Color vs Flavor Revisited

Maple syrup has always been graded using a color standard.  Back in your grandfather’s day, color was the single most important characteristic.  The original research, conducted by C.O. Willits in the 1950s, tracked the change in color during the boiling process.  As the temperature and length of boil increased, the color moved from very light to dark.  Flavor was mentioned, but little was known about the chemistry that determined flavor.  One of the reasons for color’s importance was establishing the dollar value of the product with Light Amber syrup bringing the highest prices.  For the producer, there was little incentive to make darker syrup to sell at a lower dollar value.  Fast forward to today’s market – producers typically receive the same dollar amount for the top three grades of syrup.

When a consumer is shopping for maple syrup, they are immediately drawn to an attractive glass bottle of amber-colored maple syrup sitting on a shelf.  Nothing can ruin that image faster than opening the bottle and finding out that the syrup has little flavor or, even worse, an objectionable taste.  For decades we have been told that color and flavor are interrelated, yet when it comes to flavor, there must be more to the story than the standard color/flavor relationship.

Even though the current maple syrup grading standard includes a flavor descriptor, flavor remains one of the hardest characteristics to standardize.  We now realize that multiple factors come together to form the flavor of maple syrup.  It is a combination of microbes present in the sap that changes the liquid’s chemistry as it moves through the boiling process.  Maple sap coming from the tree is comprised of 2% sucrose sugar, minerals, and other compounds.  When microbes interact with sugar, fermentation happens.  The fermentation changes a portion of the sucrose into glucose and fructose sugar compounds.  These latter two types of sugar are called invert sugars.  During the heating process, color is formed through what is known as the Maillard Reaction.  Two things happen when sap boils, density (brix level) increases and the pH of the sap initially increases (more alkaline) and then decreases (more acidic). The color is set when the rising brix level crosses the declining pH level.  The closer this interaction is to a pH of 7, the lighter the syrup.  The higher the pH is above 7, the darker the syrup.  This process also releases a broad range of flavor compounds.  A 2009 report Maple Syrup-Production, Composition, Chemistry and Sensory Characteristics stated that “over 130 volatile flavor compounds have been identified in maple syrup.”  Many of the compounds are desirable; however, others have a negative impact on both color and flavor.  This leads to the belief that color and flavor are interrelated.  However, this is not always the case.

When we label a syrup by its color alone, the results can be deceiving.  A good example is the re-appearance of light color syrup at the end of the season.  The light color indicates that the grade is Golden or an Amber, but the flavor indicates that the syrup is sub-standard.  Dr. Tim Perkins, in a recent edition of Maple Digest, described the process.  Under normal circumstances, boiling sap is increasingly alkaline reaching a pH of 8 or 9.  As more water is boiled off, the density (brix) of the liquid increases and pH becomes more acidic. As syrup finishes, pH drops back to around 7.0.  However, this is what may occur at the end of a season where warm weather and poor sanitation has taken their toll.  Sap’s pH levels drop excessively, and the liquid becomes extremely acidic.  As a result, the pH level of boiling sap may never rise above 7.0, and the liquid reaches 66 brix before darkening occurs, causing the syrup to remain light in color.  Mother nature can easily deceive producers into thinking their season has just turned round, but the truth is syrup with light color but bad off-flavor that ultimately is not fit for sale.

This is just one of several effects caused by Sour Sap.  Sour sap/syrup is the result of excessive microbial buildup and poor sanitation resulting in the formation of a strong objectional flavor and sometimes a thick viscous syrup that is referred to as Ropey Syrup.  It can show up at any time during the season, but especially at the end of the season.  Sour Sap can be managed with proper sanitation.  However, if ignored, it can destroy the value of your product.  Producers often blame the end of the season on the emergence of buds when in reality it is the formation of massive microbial colonies in their system that is shutting them down.

Other natural off-flavors include Buddy Syrup, which appears at the end of the season when maple leaves start to emerge.  Buddy off-flavor is often confused with Sour Sap; however, the flavor is more of a tootsie roll flavor.  It is more readily identified by an overpowering smell caused by sulfur compounds formed in the tree and precipitated out during the boiling process.  Metabolism is a true natural off-flavor.  It is caused by environmental conditions that cause an increase in dimethylpyrazine amino acids in the tree.  There is very little that can be done to change the onset of metabolism, and it is often very hard to detect before the boiling process.

It is up to producers to eliminate the possible sale of syrups containing off-flavors.  Producers must realize that every time a bottle of their syrup is placed on a shelf, their reputation is on the line.  For the consumer, the choices are simple when it comes to buying a product off the shelf.  It comes down to complete product satisfaction and a repeat customer or fool me once and you will not have a second chance to fool me again.

Raising the Bar on Syrup Quality

Maple grading and syrup quality are major topics at just about every maple winter meeting. Why has this topic taken on a heightened sense of importance? What is driving this interest? As the popularity of maple syrup products continues to grow, we are introducing more new customers to pure maple syrup. As interest grows, so does the number of questions about content, grading and nutritional value.  Consumers are curious!

What is the difference between pure maple syrup and table syrup?

Is pure maple syrup truly a superior product?

Is pure maple syrup worth the higher price?  

In most stores, you can find maple syrup right above the pancake flour. Shelf space is minimal and is often shared with Log Cabin, Mrs. Butterworth, and other corn syrup derivatives. The first thing consumers notice is that pure maple syrup is substantially more expensive. They may also take time to read the labels. The lower priced competition has a multitude of ingredients. Many ingredients are difficult to pronounce and not something a savvy customer wants to consume. So, they gravitate to the pure maple syrup which contains only one ingredient, Pure Maple Syrup. Many assume that because they are paying a premium price it must be a premium product. Consumers today assume a direct relationship between price and quality, and for the most part, do not mind paying a premium price for something they truly enjoy.

You only have one opportunity to make a good first impression!

There is variability in pure maple syrup sold across the country. There are USDA Standards for color and density. Density is straight forward, at least 66.0 or 66.9, depending on where you live. But grading standards by color can be confusing. To add even more mud to the water, many states do not require grading; color grading is voluntary. Remember, much of the syrup marketed in the US, especially outside the maple producing regions, is sold in box stores.

Most of the time, syrup sold in a box store is good syrup. It is sweet and with an excellent maple flavor, but occasionally there is a surprise. Until a bottle of syrup is opened and tasted, a bad bottle of syrup often looks exactly like good syrup; although, there is a tendency for poor quality syrup to wear a more generic label. You might compare buying a generic bottle of syrup to buying a box of “Cracker Jacks”, you are wondering what sort of prize will be inside. Customers can avoid bad surprises by buying from local producers who confidently and proudly attach the name of their operation to the label.

The flavor of our maple products is the single most important aspect of maple grading. Flavor more than anything else sells the product; however, grading for flavor is also one of the least understood aspects of quality syrup production. Syrup flavor varies for a multitude of reasons. Some would say it is subjective, but it is not. Each grade has its own identifiable and unique flavor profile. Because each grade is unique and prized for its own reasons, blending grades is discouraged and should be avoided. However, blending syrup grades is not restricted and it does happen. So, what exactly happens to flavor when two grades of pure maple syrup are combined to achieve a more desirable color? To put it simply, colors blend but flavor does not. Blended syrup might look attractive, but the flavor is just off. While the average consumer may not detect the difference, a discerning palate will.

If the following principle is true, for every effect there is a cause, off-flavored syrup can often be traced back to mistakes made by the producer. No one who has ever run an evaporator will deny that. Ten minutes too long on the evaporator, poor sanitation or running too late in the season, can all result in off flavors and sub-standard syrup. Mistakes happen, and in most cases, they are not intentional. That syrup should be allowed to enter the on-the-shelf marketplace. To salvage the syrup, these mistakes often end up in a barrel sold on the bulk market for whatever price the producer can get. This is what everyone does, right?!

Overall, the industry does a good job of grading density and color and is gradually placing more emphasis on quality. However, it is the responsibility of everyone involved to know when something has gone wrong. Because we are selling a food product, we need to know where to draw the line. We need to encourage producers who want to learn more about the process of making quality maple syrup to attend local or regional maple grading and quality workshops. While state regulations may enforce a bare minimum, a state’s producers should strive for better than just barely passing. Raising the bar on maple syrup quality can only be achieved through mutual cooperation and education at all levels of the industry.

 

Footnote: Substandard syrup quality and grading errors aren’t just a brick-and-mortar problem.  Check out this article from The Maple News, courtesy of research done out of University of Vermont, that examined online syrup sales and these exact same issues.