How to Make Maple Syrup Part Three: Boil The Sap.

Collect the sap in a big container.

 

Set the fire and get your wood inside the saphouse (you don’t want to open your doors too much during the boil).

 

This is our rig:

Wood goes in the doors at the  front and the fire roars the whole length of the arch, heating the sap in the pans. Smoke roars out the stack at the back.

The boiling process is hard to describe but it’s actually pretty simple.  It looks like a load of bubbles if you don’t know what you’re looking at, so here’s a handy diagram:

Sap is 2% sugar, so 98% , which is mostly water, needs to be boiled off to make maple syrup.

Water boils at 212F (100C)  but syrup boils higher, at 218 (103.33C), so you want to boil off all the water so all that’s left is syrup.

Sap comes in at the back, next to the stack and is brought down a pipe to the front. It moves through the pans, warming and becoming more concentrated as it goes.

By the time it gets to the front pans it’s pretty concentrated. The front pans are shallower and hotter and liquid boils off quicker here than in the back. It moves through the front pans and finally reaches 218F (103.33C) – syrup!

 

Boiling off the water  can get pretty  exciting. The back pans, mid boil.

 

Feeding the fire. Every five minutes or so, for hours. Try to keep the doors open for less than 15 seconds. Sometimes the doors go bright red. We’ve gotten the temperature up to 950F (510C)

 

The front pans. You can see the gradient here. Sap is coming in from the right and hardly boiling at all. As it moves across the  pans, it boils higher and higher. By the time it gets to the draw off point (top left), the bubbles have gotten bigger, the colour darker and the liquid is a lot denser, so the bubbles are popping, not bursting.

 

Watch the bubbles, the thermometer and the gallon container.

 

Syrup!

 

 

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