From Tree to Table: Maple Syrup Harvesting

Did you know that maple trees must be 40 years old to be ready to be tapped for sap? As a state, Michigan ranges 7th in maple syrup with more than 110,000 gallons of this liquid gold being produced in 2017. To understand the harvesting process, I called up local farms 4D Acre Farm in Hawks, MI and Britt Family Pure Maple Syrup Farms in National City, MI for the details.

Here are the steps Michigan sugarbushes follow to take the sap from tree to bottle.

1. Timing

Farmers know it’s time for harvest when the days get above freezing but drop below freezing overnight. Each year is different, but is usually between the end of February and early March. The tapping season lasts between four and six weeks. 

2. Collection

The Reverse Osmosis machine removes 75% of the water in sap.

Farms use tubing and vacuum systems to increase the amount of sap harvested. Trees are tapped at a specific height to maximize sap extraction and tubes guide the syrup to a central location, or pump house. Britt Family Pure Maple Syrup uses a vacuum to pull the sap into the main line and then into the sugar house. These modern changes save farmers time and allow them to tap more trees. Taps are a closed loop system and keep the sap from bugs and dirt. The sap that comes out from trees are 2% sugar and 98% water.

3. Reverse Osmosis

Nathan at 4D Acres Farm sends his sap through a reverse osmosis process. He compared it to a giant water filter that can process 750 gallons of water an hour. This process filters out 75% of the water in the sap, which saves fuel in the evaporation stage. When the liquid leaves the machine, it is 11% sugar.

4. Evaporation

The filtered sap is put into a large vat over a heat source. Britt Family Pure Maple Syrup uses fuel to heat their process, though some facilities use wood.  The sap is heated to 219 degrees F to evaporate out more water. The final product gets darker as the sugar caramelizes which creates the brown color and a richer flavor. The evaporation process is complete when it gets to 66.5 to 67 brix. Brix is a measurement for amount of sugar dissolved in liquid. This concentration is the appropriate sweetness and has made the syrup a shelf stable product.

5. Filtration

Next, the now syrup is sent through a filtration system. This removes calcified minerals that drop out of the solution and creates a smooth final product.

6. Storage

The syrup is stored in various containers depending on the producer. It stays there until ready to be bottled.

Photo from Britt Maple Syrup

7. Bottling

If the syrup is not packed right away, it is reheated to 180 degrees to meet state health codes and food safety standards. The syrup is heated and poured through a spout into bottles and heat packed. This is an additional measure to prevent mold growth or contamination. 

8. Ready to eat!

After packing, syrup is ready to be sold and put on pancakes, roasted on nuts, or added to marinades. Maple syrup farmers like to remind costumers that syrup can be used for more than a breakfast condiment. 

Now that you know how syrup goes from tree to bottle, go and find some Michigan maple syrup at the farmers market or local foods store here

Elise Gahan is a dietetic intern with a master’s degree in nutritional science through the University of Michigan School of Public Health.