Sap Flow Overview

The weather has taken a turn for the warmer in the last week, and across the province nighttime temperatures are forecasted to be above freezing for next week. Many producers are seeing this as signaling the end of this year’s short maple season.

While 2020 was an excellent year for maple syrup, with a few exceptions, 2021 saw decreased syrup production across the province. The size of this decrease varies as producers are reporting anywhere from 10-80% less syrup than last year.

This week, many producers reiterated that their crop was darker than previous years. Some also reported the worst sugar sand/niter and filtering issues that they have seen in a long time, but others have had average sugar sand and some even produced the clearest syrup they have ever made. Sap sugar content has dropped in the past week for most, but syrup flavour is still good to excellent throughout.

In terms of markets, some producers expressed concern that they would have trouble selling their large quantities of dark syrup. Other producers are concerned that they will not have enough syrup to fill the demands of their regular customers, as most have low, if any, inventory left over from last year. It will be interesting to see if this year’s supply affects bulk prices.

Southwest Region

The majority of producers here have ended their maple seasons.

Waterloo-Wellington Region

On average, producers have made between 50-75% of their crop. Some outliers made less than 30% before needing to stop for the season.

Toward the north of the region, soft maples are budding and have been shut down, but hard maples are still running with relatively clear sap. Producers took advantage of the warm weather last week to clean out pipes and equipment in anticipation of one or two final runs toward the end of this week.

Grey-Bruce Region

Producers report having made 50-80% of their crop. Some ended their seasons last week, and many others are expecting it to end very soon with a reduced crop. The size of sap runs last week ranged from partial to very large. Sap sweetness ranged from 1.3-2%. Most sap still appears to be clear, with a few reports of cloudiness in the last couple of runs.

Most are making majority amber syrup, with good to excellent flavour and few filtration problems.

Some producers used the warm weather to flush out sap collection tubing and equipment in the hopes that cooler weather would renew sap runs.

Central Region  

Producers in Quinte, and Lanark report making between 50-80% of their full crop. This week has brought good runs, though some are anticipating that this will be the final push before the season ends. Sap ranges from clear to slightly cloudy, but no microbial taste.

Buddy syrup has been detected in several operations in southern Kawartha. Some producers are halting production having made 60-70% of the crop of an average year.

Eastern Region and Ottawa Valley

Producers have made 25-60% of their annual production. Sap is still clear and syrup colour is mostly dark, with some amber and some very dark. The general consensus is to continue production for as long as possible, as temperatures are fairly promising this coming week. However, once things warm up the week after, producers said that they will likely stop.

Algonquin Region

Crop production reports vary, with some producers having made 30% of their annual production while others expect to be up to 75% by the end of today. The last week saw very good sap flow, though volumes were below average for this point in the season. Sap sugar content is low in this flow as well, and syrup colour is amber to very dark.

Algoma Region

Producers report making 20-50% of their annual crop; some are on schedule while others are producing much less than in previous years. Sugar content still seems to be holding steady. Sap runs have been quite small and sporadic compared to previous years. Sap is still clear, and syrup colour is mostly amber with some dark.

Why does syrup change colour during the season?

The short answer is – friendly microbes. Most producers expect syrup to be lighter at the beginning of the season and darken toward the end. However, as was demonstrated this year, sometimes syrup colour changes even in-season. This is due to the microbes changing the types of sugars in the sap.

The sugar in maple sap is mostly sucrose. Microbes feed on the sucrose and turn it into fructose and glucose.

During boiling, fructose and glucose are much more reactive with other elements in the sap, leading to colour and flavour development. In contrast, sucrose undergoes very little colour and flavour change when boiled, and will remain simple and sweet unless boiled for too long. We have these microbes to thank for complex maple flavour!

Lighter syrup will thus be produced when microbe numbers are reduced. Conditions causing lighter syrup include:

• Cleaned equipment
• Clean sap that is filtered immediately after collection
• Sudden cold temperatures that can kill a number of microbes
• Cold temperatures that keep the number of microbes low
• High sap flows whose volumes move too quickly for microbes to transform a significant portion of the sugars

Many producers made darker syrup this year. This may be a result of the unusual warm weather in many parts of the province giving microbes an earlier start than usual.

If you wish to contribute updates, please get in touch:

Jenny Liu
jenny.liu2@ontario.ca
519 835 5872
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