Here is the finished product. Read on to see how we got it.
We started with the pot on the right full. About 4 gallons of sap. That all came from 1 tree in about 3 days.
After about 6 hours boiling outside on the grill burner it evaporated to about 2 cups. Then we brought it in to finish it off. You are not supposed to boil sap inside because of the crazy amount steam that comes off of it. If you start researching maple syrup making you find out all sorts of rules about the right and wrong ways to do it. The goal is to reduce the sap down until it reaches 7.5 degrees above YOUR boiling point. So the first step to that is finding out what your boiling point is. It can vary on elevation and even weather. Ours was 208.4 degrees. Everything I read said to use a candy thermometer. I tried that but opted to use my digital meat thermomter because it was easier to read and seemed more accurate. But I don't recommend that unless you own the t.v. infomercial Ove Glove made out of KEVLAR. It gets HOT!
Here it is toward the end stages. It starts out as clear as water and toward the end starts to take on the maple syrup auburn color. It's almost done! You definitly want to keep a very close eye on it at this stage because once the temp starts rising it is a matter of minutes. And you do not want to do all that work and end up over boiling it.
This is the finished product. About 1 3/4 cup 100% pure maple syrup. The ratio from sap to syrup ends up about 40 to 1. So 40 gallons of sap will end up about 1 gallon of syrup. Or 4 gallons of sap will end up about 375 milliters=1 1/2 cups.
The end result.