I'll bet it took 4-5 hours to boil that down. A couple of things that will improve your efficiency. Find a larger, flatter pan. A large baking pan with 4-5" sides like a lasagna pan will increase your surface area, both in contact with the stove and air and will allow water to boil off faster. Keeping less sap in the pan and adding in small amounts (I use a camp cup with the wire handle for a dipper) will allow you to maintain a better, faster boil. When you get the hang of it, you can add a cup at a time without losing your boil. Also if you have a metal container to hold sap that can be placed near the stove, it will pre-heat the sap allowing you to bring it to boiling temp faster. If you don't already have them, you'll want some 5 gal pails or jugs with lids to store sap in a cool place. You'll soon be overflowing with sap! Even the new pails, I clean with vinegar and water, then rinse a couple of times to remove any plastic or other residue. Can't tell if your stove pipe has a damper installed. If not, add one. You'll be able to regulate the heat better and keep a good boil without burning through your firewood too quickly.
I did my first run yesterday, boiled down about 15 gal of sap yielding 5 pints of syrup. Had a very dry fall last year, and yield per gallon seems to be higher than usual. Ate some on French toast, it was delicious. Hope your first syrup worked out. Will try to get some more pictures of the process today.
Curious to know how your walnut syrup turns out. I've heard it's quite delicious.
