We boil with a wood-fired stove with a stainless steel pan on top. The pan is partitioned with small gaps in the bottom of alternate corners of the partions. Sap runs in at the smokestack end of the pan, which we fill to a depth of about 1 1/2". We steadily trickle sap in as it evaporates, adjusting the flow with the red-handled valve as shown in the below photo. Since liquid seeks it's own level in the pan, it slowly runs in one direction as it replaces the evaporated liquid. The first section is therefore nearly raw sap, the next a bit sweeter and so on, until the section at the opposite end becomes syrup.

It takes about 40 gallons of sap to make one gallon of syrup! We have two sets of thermometers to help us determine when a batch of syrup is ready, which is 7 degrees above the boiling point of water. At that time we open the yellow-handled valve and draw off 1 1/2 gallons or so. We might draw about 4 batches in a ten hour day of boiling.

Harmless minerals, known as sugar sand, will slowly settle in finished syrup. For the final filtering, we either allow the syrup to settle and then pour the clear syrup off the top, or we do the final filtering through prefilters and a thick syrup filter.

The clear syrup is heated to at least 180 degrees on a wood stove in our "sugar shack" and then canned.

This is a photo of the A-frame where we do our boiling. The stove burns so cleanly very little smoke comes out of the black smokestack, but as you can see there are clouds of steam under the right conditions. At the opposite end is a pile of dry firewood. At the near end the white cubic object is our sap feeder tank, in which we store sap to be gravity fed into the boiling pan. The tank is draped with a clean white sheet to keep it cool in sunny weather.