Harvesting Sap: A Primer to Tapping Trees for Syrup Making

Updated February 2023

Harvesting sap for syrup making has become one of our favorite harvest activities of the year! The sap moon, typically the full moon in late February or early March, marks the beginning of the flow of sap. The flow of sap in trees is a simple miracle, one of abundance in a time of hibernation. When all the world seems to be asleep blanketed under a layer of snow, the sweet flow of sap begins in the trees around us. Of course, you cannot see it when you simply look with your eyes, but as you feel the warming of days contrasting with the freezing temperatures of the cold dark night, you can feel the changing of seasons present in the air and with it comes the sap flow; the sweetness an indicator of the sweetness to come as spring approaches. 

Practicing gratitude and mindfulness in the harvest

We owe our knowledge of sugaring to our Indigenous brothers and sisters, who have harvested the sap flow for generations, returning gratitude to the trees and the land through stewardship and care. In her essay titled “Maple Sugar Moon” in Braiding Sweetgrass, Robin Wall Kimmerer shares the story of the Anishinaabe Original Man, Nanabozho, as he finds his people lying lazily beneath a maple tree, with their mouths open catching the falling syrup from the trees. “They had become lazy and took for granted the gifts of the Creator” … so he “went to the river and dipped up many buckets of water. He poured the water straight into the maple trees to dilute the syrup. … Today, maple sap flows like a stream of water with only a trace of sweetness to remind the people of both possibility and responsibility. And so it is that it takes forty gallons of sap to make a gallon of syrup.” (Braiding Sweetgrass, Robin Wall Kimmerer, page 63).

To harvest sap from a tree is a great responsibility and ought not be taken lightly. Harvest only from trees that are large enough to support themselves and you as well - with a diameter of at least 10” and in good health. Trees with diameters over 18″ can accommodate two taps, while those with diameters over 25″ can accommodate three. Throughout the rest of the year, offer gifts in return - spread compost at the base, care for the health of the tree, say thank you and reflect on the many gifts the trees offer us throughout the year: shade, oxygen and shelter. 

Tapping a line of Black Walnut trees along the edge of our neighbor’s homestead

Materials needed

• Power Drill

• Sharp drill bits, sizes to correspond with chosen spout size and dropline size

• Hammer

• Spout or Spile, 1-3 per tree depending on tree size
  The spouts, also called spiles, are used to tap into a hole in the tree and allow the sap to flow out of the tree and into a collection container. There are various sizes available on the market, and spiles can be either plastic or metal.  (Here is the one we use)

• Droplines, 1 per spout
  Droplines are plastic tubing that is used to connect the spile to the collection vessel. Some spiles don’t require droplines, but many do.  (Here is what we use)

• Collection container with lid (at least 1 gallon capacity), 1 per tree
  You can use any variety of collection containers, though we recommend using something that is easily cleanable and has a secure lid to keep out rain, snow and debris. We use 5 gallon food-grade buckets with lids. You can also use cleaned and empty milk jugs or any other food-grade container. 

• Filters
  Filtering your sap before and after cooking helps to remove any debris and sediment that collects in the sap, resulting in a cleaner finished syrup (Here is what we use) 

• Heavy-bottom Pot

• Candy Thermometer

Preparing your materials

Clean all of your tapping materials with hot water, boiling to sterilize. Avoid the use of soap, as it is hard to remove all the residue and can affect the final taste of your syrup. 

Assemble the spouts with droplines by connecting droplines to the down-spout of the spile. Using a drill bit that corresponds with the diameter of the dropline, drill holes around the top edge of the container. Insert the droplines into the holes, with the appropriate number of droplines per the size of the tree. 

Tree Selection

While the Sugar Maple is the most commonly tapped tree for making syrup, there are many types of trees that produce a sap flow with a sugary sap that can be cooked into syrup. In our experience, we have tapped primarily Black Walnut trees, which grow in abundance near our homestead. Other trees that produce sap include: Silver maples, Boxelder and Birch trees to name a few. Here is a great resource that explores the differences of these different trees (and more!) for syrup production: 27 Trees to Tap for Syrup. Each variety of tree will yield a slightly different flavor of syrup. Of course, you can combine the saps of many types of trees, but it may also be fun to keep them separate to taste the variances!

Identify your tree and inspect it for good health. Avoid harvesting from a tree that has signs of damage, such as splitting or bark peeling, as this will not only produce a lower yield but may also further damage the health of the tree. 

A sample of our set-up: holes drilled on the east, south and west side of a black walnut tree, into the ridges of the bark, spiles tapped into the tree with downspouts emptying into a 5 gallon bucket with a lid.

Drilling a hole

Identify the south-side of the tree - you will place your holes about 18” apart on the East, South and West sides of the tree, as these sides will be warmed by the sun and produce the best flow of sap. Only tap trees with a diameter of at least 10” and in good health. Trees with diameters over 18″ can accommodate two taps, while those with diameters over 25″ can accommodate three. 

Using a power drill and a sharp bit (very important that it’s sharp, so the hole is smooth and clean) that corresponds with your chosen spout, bore a deep hole in a tree to a depth of 2” to 2 ½” or until you reach the lighter inner sapwood of the tree. Blow out any wood shavings or pulp with a quick, close breath. For reference, you can wrap a piece of tape around the drill bit 2 ½” from the tip to use as a guide. Drill at a slight upward angle to promote a downward flow of sap from the hole. The hole should be situated at a comfortable working height, approximately 2′ to 4′ above the ground. If you tap the same tree each year, drill holes at least 6” apart from previous holes to allow the tree to recover from the holes and remain healthy.

Tapping the Tree

Place the pointed end of the spile (another name for the spout) in the hole and gently hammer into place, with the droplines pointing towards the ground and the collection container resting on the ground at the base of the tree. Collect the sap daily by pouring it into a collection bucket or replacing the current collection container with an empty one. Refrigerate the sap in a large covered container until you’re ready to boil it down. Filter your sap through a filter or two layers of cheesecloth before boiling to remove any debris or sediment.

Boiling the sap

Bring the sap to a boil in a large heavy bottom pot over high heat. Then, reduce heat to medium high and maintain a low boil. Using a pan with a larger surface area will help the cooking process to progress quicker, as the steam can cook off more quickly. It is best to start with at least a gallon of sap to prevent the final syrup from scorching on the bottom of the pan. As the water boils off, you can add more sap.

The temperature of the sap will indicate the sugar concentration. Using a candy thermometer is a great way to measure the sugar concentration. At 215 degrees F, pour your syrup through a filter to remove excess minerals before cooking to the final temperature between 217 and 219 degrees F. This is also a good time to transfer the syrup to a smaller pot to finish the cooking process so the syrup doesn’t scorch on the bottom of the pan. The syrup is finished when it reaches the optimal temperature between 217 and 219 degrees F - the higher the temperature, the thicker the finished syrup will be. If you don’t have a thermometer, you can also use a clean spoon to do a “drip test” - dip your spoon into the thickened syrup and stop cooking when the syrup drips off the spoon in a thick drip. Note that the syrup will thicken as it cools. 

One gallon of sugar maple sap cooks into approximately 4 ounces of syrup. Other tree saps tend to have a lower sugar concentration, though final yields depend on the time of harvest, the location of the tree, tree species and other environmental factors. For example, trees that are higher on a slope or hill will tend to have a higher sugar concentration while trees at the bottom of a slope or hill will tend to have a lower sugar concentration, as they are subject to more water flow as snow melts and flows in the ground. There are many factors that can affect the final yield, and really, only time and experience will tell! 

Bottling the syrup

Using a metal funnel lined with a clean filter, pour the hot syrup into clean glass bottles, and cap them. To prevent the bottles from cracking, warm them by filling with hot water and pouring it out right before filling with syrup. To bottle for shelf-stability, fill with hot syrup (at least 214 degrees F), cap with a clean, solid lid (i.e. not a pour top) and invert the bottle until it’s cooled. Bottled this way, unopened bottles should remain shelf-stable for two years. After opening, store syrup in the fridge for up to a year. Some minerals and sediment may settle to the bottom of your finished syrup - it’s still edible, just slightly different texture and flavor! If you choose to bottle at a cooler temperature or into a container that you’re not able to invert, just store your syrup in the fridge to prevent spoilage.

End of season considerations

After the harvest season, typically when the temperatures no longer fall below freezing, it is important to clean up your materials and tend to the trees. Remove all taps from the trees and gather the materials you’ve used. Clean and sterilize all of your spiles and downspout tubes and allow to dry completely before storing. Do not plug the holes you’ve drilled in the trees - instead, allow the tree to recover on it’s own.

Think of reciprocity - how will you show your gratitude to the trees and their generosity? Will you plant more trees in your community? Offer compost to the trees who have shared their abundance? Or perhaps you will say “thank you” as you crack open a bottle of liquid gold and pour it a top a tall stack of pancakes on a cozy weekend morning. There are endless ways to share your gratitude as you enjoy the golden syrup of these crisp winter days throughout the year!