Boiling

The process of making maple syrup requires that the sap collected directly from the tree be concentrated from it's approximate 2.5% sugar content to a 66% sugar content to become maple syrup.

The sugar content (Brix) of the sap determines how much sap is required to make a gallon of syrup. We use the "Rule of 86" to make our calculation. Using our estimated 2% sap, we divide that number into 86. Which gives us a figure of 43 gallons of sap (86 divided by 2) needed to make one gallon of finished syrup.

The easiest method for us is to boil the sap until it reaches 66% Brix. Our wood-fired evaporator can boil approximately 130 gallons an hour and requires adding wood very 10-15 minutes. The cleaner the evaporator and faster the sap boils the better the finished product.

Maple syrup boils at 7.1 degrees Fahrenheit above the boiling temperature of water, so a good thermometer can be used to determine when it's syrup and and the density can be measured.

°Bx
Degrees Brix (symbol °Bx) is the sugar content of an aqueous solution. One degree Brix is 1 gram of sucrose in 100 grams of solution and represents the strength of the solution as percentage by weight (% w/w). If the solution contains dissolved solids other than pure sucrose, then the °Bx only approximates the dissolved solid content.

Vapor pressures and boiling points of substances can be affected by the presence of dissolved impurities (solutes) or other miscible compounds, the degree of effect depending on the concentration of the impurities or other compounds. The presence of non-volatile impurities such as salts or compounds of a volatility far lower than the main component compound decreases its mole fraction and the solution's volatility, and thus raises the normal boiling point in proportion to the concentration of the solutes. This effect is called boiling point elevation. As a common example, salt water boils at a higher temperature than pure water.

In other mixtures of miscible compounds (components), there may be two or more components of varying volatility, each having its own pure component boiling point at any given pressure. The presence of other volatile components in a mixture affects the vapor pressures and thus boiling points and dew points of all the components in the mixture. The dew point is a temperature at which a vapor condenses into a liquid. Furthermore, at any given temperature, the composition of the vapor is different from the composition of the liquid in most such cases. In order to illustrate these effects between the volatile components in a mixture, a boiling point diagram is commonly used. Distillation is a process of boiling and [usually] condensation which takes advantage of these differences in composition between liquid and vapor phases.

130 gallons per hour
212°F (99.98°C)
Water, Boiling point