I can't wait until the trees start to flow...it's a little reminder to me that spring is around the corner. I have ~10 sugar maples that are over 100 years old, so they are huge and give me lots of sap. We make only enough for us and for Xmas presents. We've made as little as 2 gallons of syrup to over 7 gallons.
You will need around 40 gallons of sap to make 1 gallon of syrup!
We use a 3 burner camping stove and picked up 3 - 10 gallon pots from a kitchen supply store, we have a octogon building we use as our sugar shack. My DH has a method where he keeps track of the amount of sap he boils down before we bring it in the house to finish off. He will use 2 of the 10 gallon pots and start them boiling together. When boiled down enought he pours the sap from 1 pot to another and adds no more to the pot with the sap. Otherewise you forget how much you have in there. When we first started to boil sap we would just keep adding and testing. At least 1x per season we would be outside and think, boy does that cooking syrup smell good. That is NOT a good sign, it means that it has boiled over. One year the syrup was burned hard to the pan, we left the pan sit for a year and had to use a sandblaster to get the burnt sugar out. What a mess!
How long can you keep sap and store it? That is a tricky question, because it depends on the temperature it is kept at. But the longer it sits the more cloudy it gets and a stronger flavored syrup you get. The sap will go sour if left sit too long.
Let us know when the sap starts flowing in your area!