Making Maple Syrup
Making maple syrup takes lot of time, can be hard work and is very rewarding. The sap season in our region of Lanark County typically starts in mid-March and runs 4 - 6 weeks. However, the work begins long before with cutting & splitting firewood, installing and maintaining vacuum tubing, preparing equipment and tapping the trees.
Making 1 Litre of maple syrup generally takes about 40 litres of maple sap. The ratio varies depending on the sugar content of the sap, which averages about 2.5% and will change over the season. The sap is concentrated into 100% pure maple syrup by cooking the sap to boil water off as steam, the only ingredient being maple sap. No preservatives, additives, or colouring is added. The finished product is a 100% pure Grade A maple syrup!
Syrup flavour differ greatly from region to region. We believe what makes our syrup one of the best is the "Terroir" of our property which is defined by the uniqueness of the geology, geography and climate. Our trees grow on shallow mineral soils that have developed from the underlying granitic and mafic bedrock.
Syrup Production on Our Farm
Producing maple syrup is a year round activity that has many beneficial impacts.
Our forest management plan includes a combination of selective cutting and planting of new maple seedlings each year.
Maple trees - like plants in your garden - require space to grow. Trees that yield the highest amount of sap with the highest level of sugar content, are those with the largest crowns. When we're cutting firewood from our bush we're creating space for trees to expand while leaving a mix of other species like hemlock and oak.
Tapping / Collection
We use a mix of vacuum & gravity tubing
We use a combination of 5/16" tubing on vacuum, 3/16" on gravity and traditional buckets. The use of 3/16" tubing is a relatively new practice in maple bushes and follows recent research that has shown the natural gravity over an adequate slope can result in similar vacuum levels at the tap holes as traditional mechanical vacuum on 5/16" tubing.
Preparation for tapping begins early in the year with clearing the tubing lines of broken branches, repairing animal damage and replacing spiles that have been used for several seasons. The food-grade tubing is designed to last many years and every year we are replacing older lines. Research has shown that sap production decreases each year a spile is re-used as result of bacteria build-up. We tend to replace our spiles every 2-3 years and are beginning to experiment with new styles that get changed each year.
Taps are always drilled into fresh white clean wood at depth of about 1.5". Tappers learn to recognize previous tap holes by the scarring in the bark and drill the new tap holes away from old ones. We use 1 tap for trees 12” to 18” in diameter, and 2 tap-holes for larger trees and no more no more than 2 tap-holes per tree.
We typically have 10-15 taps on a 5/16" lateral line connecting to larger 3/4" and 1" mainlines (and even more taps on 3/16" lateral lines). The mainlines direct the sap into large storage tanks where it is then moved to transfer tanks and brought back to the sugar house by tractor.
Energy & Time Savings
Sap is processed through Reverse Osmosis (RO) equipment to remove water from the sap before it enters the evaporator. "Raw" sap typically has a sugar content of 2.5 - 3% sugar. Sugar concentration will vary between different maple species and throughout the maple sugar season.
The sap is pushed through the RO membrane cylinders which allow the water particles to pass through without the sugar. In our operation, the sap is circulated through the RO until the concentrate reaches as sugar content of 8-12%. Other Producers may process the sap to even high concentration levels depending on the size of their operation and type of equipment.
The RO process has no affect on the taste or quality of the maple syrup.
The biggest benefit is the time savings required to cook sap on the evaporator. Increasing the sugar concentration 4x to 10-12% results in 1/4 of the time required to boil the sap to syrup and 1/4 of the amount of firewood required.
High Efficiency Wood Burning
One of the most impressive pieces of equipment used in making maple syrup is the modern evaporator made with all stainless steel pans and components. An Evaporator is typically comprised of a flue pan, also called an evaporator pan which has raised flues which create more surface area for boiling, and two or more flat bottom finishing pans. Evaporators can be as simple as an iron pot over the fire.
Our evaporator is manufactured in Quebec by CDL and is a high efficiency air-forced combustion wood burning design. It results in complete combustion of the wood and very hot temperatures depending on the type of wood being burnt.
The sap levels in the flue and finishing pans are are controlled by float values. As water is evaporated the concentrated sap moves forward to the finishing pans and the floats lower to allow new sap to enter the pans.
The sap becomes syrup once the sugar concentration level reaches 66 Brix - a measurement to used to measure sugar content of syrup and wine. This level is usually achieved once the syrup reaches a temperature of 219 F which is 7 degrees above boiling water. Since the boiling temperature will vary because of air pressure and weather we use a number of different measurement instruments including a hydrotherm and a digital refractor to ensure we have reached the correct density.
The syrup comes off the evaporator using an automated take-off value connected to a thermometer in the finishing pan.
Maple syrup coming directly off the evaporator must be filtered to remove sugar sand and other impurities that will cloud the final product. Proper filtering will result in a crystal-clear product and can be done using a combination of paper and wool or polyester filters, or with filter presses.
Filter presses such as one we use, have multiple plates. Each plate is covered with filter paper and separated with a spacer section that allows the filtrate media to build up and coat the filter paper. The syrup coming off the finishing pan is mixed with diatomaceous earth (DE) which acts as a filter media. It is actually DE that does most of the filtering.
The syrup is pumped through the filter press and into a heated water-jacketed tank for bottling. Before the syrup can be bottled, it must be heated to a minimum temperature of 88 °C (190 °F). This will ensure that the syrup will sanitize the container and create a tight seal with the cap. The minimum temperature can vary depending on the size of bottle. Care must be taken to watch the temperature because getting the syrup too hot can also result in crystalization.
Each batch is graded: the bottles labelled with a lot number for traceability.
Our syrup is available in glass and plastic container sizes of 1 Litre, 500 mL, 250 mL and 50 mL Specialty Maple Leaf bottles.
Syrup is graded to be sold according to colour.
The Ontario Grade A maple syrup grades are:
- Golden ... for a delicate taste
- Amber ... for a rich taste
- Dark ... for a robust taste
- Very Dark ... for a strong taste
Each day that we boil, we take a sample of the finished syrup and compare it to colour samples.
Generally the syrup is lighter at the beginning of the season and becomes darker as the season progresses, and at the same time the maple flavour becomes stronger.
Most of the syrup produced on our farm is either Amber or Golden.
Preparing for Next Year
The syrup season is not done till all the equipment is washed, taps removed, lines sanitized, and firewood prepared for the following year!
As soon as maple buds appear it’s time to pull the spiles and sanitize the lines. When each spile is removed, a small amount of isopropyl alcohol is injected into each dropline and the spile inserted into the T-connector, creating a closed loop. The alcohol remains in the tubing throughout the summer to prevent bacteria growth. At the beginning of the next season, after tapping, the initial sap is allowed to drain onto the ground to flush the lines.