How Much Sap Does it Take to Make a Gallon of Syrup?
By far, the most common question that we get asked about maple syrup is “how much sap does it take to make a gallon of syrup?” Many people’s experience with making pure maple syrup only goes as far as perhaps visiting a sugarhouse in the late winter and having a pancake breakfast. Seeing the steam coming from the evaporator is quite the sensory experience, but I feel like what is actually happening doesn’t really sink in.
To start to answer the question, let’s go over what maple syrup is made from; sap! The maple trees sap contains sugars that, if not harvested, feed the tree and help it to produce new leaves after a long winter. Raw sap is a clear, odorless liquid that is only slightly sweet to the taste.
While generally any maple tree can be tapped for its sap, the sugar maple tree is preferred as the percentage of sugar within the sap is typically greater than other species.
This image (from SmokyLakeMaple.com) gives a visual representation of different sugar contents (% brix) to make a gallon of syrup.
Typically, sugar maple sap will be around 2% sugar and while this can vary a bit, the general rule is that it will take about 40 gallons of sap to produce one gallon of syrup. (For a much more detailed article about the topic, including lots of mathematical formulas, check out MapleResearch.org’s article on “The “Jones Rule of 86” Revisited”)
The trees on our property are primarily red maple trees and while they produce lots of sap, the sugar content in that sap is very low. We average about 1.1% sugar in our sap so that puts us close to 80 gallons of sap for every gallon of syrup. Many traditional sugar-makers wouldn’t bother with a sugar content this low, but through the use of reverse osmosis we are able to reduce the water in the sap to bring the sugar content up to a level that makes boiling into syrup not only realistic, but quite efficient.
The water in the sap needs to be removed and boiling it is the traditional way that this is done.
Our current evaporator can evaporate about 15 gallons of water per hour so if we boiled raw sap from our trees we would have to boil for almost 5.5 hours to produce one gallon of syrup! After we process the sap through the RO system we have removed enough water to make the sugar content 8%, which only takes us about an hour to make that same gallon of syrup!
The next time you see a plume of smoke and steam coming from a sugarhouse, be sure to stop in and say “hi” to the sugar-maker inside; the work they are doing is a labor of love that takes a long time to come to fruition. Without some modern innovations, many of us wouldn’t be able to share in the experience that, at least for us, defines the end of winter and beginning of another year!
