Learn how to make maple syrup with this simple maple syrup evaporator. I’ll show you how to tap and collect sap from your sugar maples and then boil down the sap. This setup uses propane and 2 outdoor propane stoves.
What’s great about this simple maple syrup evaporator rig is you can walk away from it. You don’t have to watch it constantly. I have mine outside the kitchen, and every 15 min or so I go out and check it.
I found a used large stainless steel pot that was probably used to boil clams, and I found a large shallow stainless steel bowl at the dollar store. The idea behind this DIY maple syrup evaporator is the cold sugar maple sap is brought up to a boil in the first large pot, and then it is ladled into the shallow finishing pan to be boiled down into maple syrup.
Sugar Maple Sap becomes maple syrup when the sap reaches 7.5 degrees F above the local boiling point. Boil a small pan of water on your stove and when it boils, measure the temperature with your digital thermometer. Add 7.5 degrees to that temp – at our house the boil happens at 210F – and when the sap reaches that temperature, it is now syrup. Quickly turn off the heat on the finishing pan burner, and strain the syrup in to jars. If you are up to it, you can let the sap boil to a slightly higher temperature for a slightly darker syrup – be careful not to burn the finishing pan.
Parts You Need For The Simple Maple Syrup Evaporator
I strongly suggest buying a digital kitchen thermometer, old style candy thermometers are hard to use with this setup.
If you see your finishing pan foaming big time, you probably have syrup, and probably the temperature is above the ideal, turn off the propane and pour off the syrup.
The drawback of this system is that it uses quite a bit of propane, not the best use of what you’ve got. The plan is to build a wood fired evaporator next year. I have a ton of white pine from the trees we dropped that would fire a sugar shack nicely.
Maple sap becomes Maple Syrup at 7.5 degrees F above the local boiling point. Go boil a pan of water on your stove, use your digital thermometer to measure the temp at boiling. I bet it wont be 212F, but probably lower. Add 7.5 to that boiling point for the temperature you want to attain.
Wide Pots work best for boiling sap
When its Syrup, the sap starts to foam up, so you have to keep an eye on the process.
Be very careful. Hot sap burns bad, plus there is open flame. Use common sense, keep kids and dogs out of the way.
The wider the pot you use, the more sap you can boil off faster. Its all about surface area. This is why evaporators are wide and shallow.
Take the pot off the propane burner as soon as you reach temp. Its OK if the temp goes a bit higher, but not much higher. I find it best to finish the boil on the stove in the kitchen. Take it inside when you are within a few degrees of syrup at your elevation.
Strain through cloth, cheesecloth, whatever you like. You will have some cloudiness in the syrup if you use cheesecloth.
I realized I bit off more than I could chew about one week into this year’s maple syrup season. Ever think about a project for months, only after you start you realize, OK what did I get myself into? That’s me this year making maple syrup.
Have to clean up the rig soon.
First I built a new homemade maple syrup evaporator, I had been building it my head since last season. I found a legal size file cabinet in Brooklyn for $50, hauled it up to the house, and started building the firebox. I bought a Harbor Freight Flux Core Welder to help with the build.
For a while now I have been wanting a MIG welder, but after learning about the flux core, it was the obvious choice, and I now had a project where it would be useful. So a deep dive on YouTube on how to weld led to our first basic flux core welding video.
I had also been thinking about getting a evaporator pan made to fit right on top of the cabinet. For the previous homemade evaporator, we used steam table trays, and that’s ok, but I wanted to boil more sap in less time.
I found a guy named Zach who was selling sap evaporator pans on Ebay, and contacted him about a custom pan. A week later a cheap maple syrup evaporator pan shows up on my doorstep. Cheap isn’t the right word, but mbe that phrase will help Zach get more biz for his site through search. Really well made is a better term to describe it.
Last fall I started collecting way too many pallets to supply the firewood to boil down all the sap I was going to collect.
Way Too Many Pallets!
All during last winter I’m eyeballing more sugar maples I can tap around me. How would I run the lines, how close can I get them to the road – too much thinking. I order more tree taps and sap lines. Sap line and taps are surprisingly cheap, BTW.
And I bought a food grade pallet tote on craigslist, which holds 275 gallons of liquid.
So I fire up the new evaporator and realize quickly I’m burning wood real fast, and not getting a lot of heat in the tray. The sap is boiling OK, but it should be really boiling or I should be throwing less wood into the firebox. The fire is racing through the cabinet and going right up the stack.
Firebox Raceway
Always fun to see flames coming out of the top of a 8′ chimney. No pictures, sorry.
So while I’m slowly boiling sap, I’m collecting A LOT of sap. I had been thinking about extending some of the sap lines I do along the road up into the woods, but I’m glad I didn’t.
The big problem with collecting lots of sap is storage. I then discover the neat pallet tank freezes. And you can’t just break through the ice in the tank like you can with an open barrel. So I had 150 gallons of sap in a pallet tote that I couldn’t get out of it. The valve on the bottom, and the water in the sap, was frozen. The tank is plastic, so you can’t heat it, or it melts. The beauty of the blue plastic barrels I use is that you can break through the ice and haul out the concentrated sap in the center, then turn it on its side to dump out the ice. Not so with an enclosed tank.
A related issue was when I wanted to run a gravity fed line from the storage area up by the garage down to the evaporator, I used the 5/8″ sap line. If it was 32F or lower outside, the sap would freeze in the feed line. I gave up and hauled it with buckets.
My two big problems were the heat racing through the firebox and sap freezing in storage.
The sap freezing was easy, sell the pallet tank buy some more blue barrels for storage.
The firebox inefficiency was not as easy. Reading on the Maple Trader maple syrup forum, many sap makers build a baffle or obstruction in the firebox to get the heat to stick around longer. My friend Bill, who I learned how to make sap from, has two bricks halfway down the firebox, covered with sand. This causes the air – heat to become turbulent (we think) and stick around longer. I read about others who put a metal baffle in the box to slow the burn. One could also put a damper in the chimney.
My experiment with pre-heating the sap by running a copper tubing around the chimney stack didn’t work. The sap just didn’t warm up very much. Copper tubing is expensive! Maybe running the tubing inside the chimney may work better.
And of course, we had the epic FAIL on a glorious winter day:
Not fun…
After this I went out and bought a food grade tank that sits nicely in my trailer. BUT, like the pallet tank, you can’t let sap sit in it, you have to get it into barrels or it will freeze. The fact that the tank sits low in the trailer (good for avoiding more spill fiascos) means I have to bucket it or pump it into the taller blue barrels. I see a pump purchase in my future…
Storage: I’ve been a big proponent of doing with less, minimalism, downsizing your junk. But making maple syrup causes you to need to store quite a bit of stuff. Kinda like beekeeping. The barrels go up in the garage, but I have to find a place for the tank.
More stuff to store
What did work quite well was lining the side of the firebox with firebrick. I found the firebrick at Lowes. It was pretty cheap – previous I always thought firebrick was expensive. This type was sold as bricks to replace cracked ones in a home wood stove. I basically leaned them up against the sides of the file cabinet. This directed heat up to the evaporator pan, and kept the sides of the cabinet cooler. With the previous file cabinet evaporator, you couldn’t stand next to the rig for too long without burning your pants.
The last thing that hampered the sap season was me. I did this all by myself. Friends would be interested, but wouldn’t show up. So if you are thinking about making maple syrup, get your friends involved early.
But I am already thinking about next year!
I will post some photos of my firebox on Maple Trader and ask the experts for suggestions. My friend Bill suggested the bricks and sand method, that is the first one I will test out. Improve the sap pre-heater. And yes, test the firebox before the start of the season. Did not think to build the evaporator in the fall and boil some water to see how it all worked.
It will be easy to sell the pallet tote to a neighbor, and blue barrels are easy enough to get.
So if you are thinking of making maple syrup, start small and involve your friends. Your eyes will be bigger than what you can get done in the 3 weeks of sap season. Learn from me!
This last weekend the temperature was around 5-10 degrees F all night and day. So this played havoc with our maple syrup evaporator operation. The line that feeds raw sap to the evaporator froze as soon as I would defrost it, so I was ladling sap in to the pan by hand.
Bigger problems were elsewhere in the yard. My main sap storage tank was frozen to the point that the drain valve froze shut. Its kinda a bulky object to work with, so it just had to sit until it warms up later this week.
But one thing I had never seen is just how frozen one of my barrels out in the wood was. These barrels sit at the end of a line of maples we have tapped. This one had so much ice in it, the lid had been popped off.
I hacked through the top layer of ice knowing there would be slushy sugary sap inside. I scooped out the sap and carried it in buckets over to the evaporator.
Usually, if I have overnight ice in a bucket, its maybe an inch thick. I remove this ice and toss it. My thinking is the first ice that freezes on cool nights has a low sugar content.
But this barrel was different. It had gotten very cold, and this was a lot of ice. So I dragged a spare barrel over and connected it to the sap line, and let this one just sit. The temperature will go up later this week and I hope most of the ice will melt. Then I can haul it to the evaporator.
Tossing ice from sap buckets is one of those contentious topics in the maple syrup world. I want to borrow my friends brix refractometer and measure the ice in the buckets and the remaining liquid to see the actual sugar percentages.
Halfway through collecting maple sap to make maple syrup, I made this video on tips on tapping maple trees and how to collect sap to make maple syrup. Shot on the iPhone, it looks pretty good.
I use tree saver plastic taps and plastic lines to collect sap, i’m finding that buckets at each tree work pretty well. I have one large barrel that collects from two trees, and its kind of a pain to get the sap out. The benefit is if the sugar maple sap runs really well, the bucket can handle the sap. One time my smaller 5 gal buckets overflowed.
There has been some discussion on how much sugar gets trapped in the ice that we remove from the sap buckets. My neighbors, old time maple syrup experts, remove the ice from their maple sap buckets. But then I was asked how much sugar is lost with the ice, and I don’t know. The questioner brought up Popsicles, and the fact that they are made with sugar that seems to freeze with the ice.
It helps when hauling buckets of sap to have them only half full, its easier on your back and you splash a lot less. I store our sap in a big new trash can on the shady side of the house that has been surrounded with snow to keep the sap cool.
Tapping sugar maple trees to make maple syrup is a big tradition in my part of Connecticut, so I wanted to show you how to tap maple trees to get maple sap to make maple syrup. We use plastic taps and tubing that are connected to buckets at the base of each tree. The advantage of using individual buckets is that some of the water in the sap will freeze in the collection bucket. The whole goal of boiling sap in an evaporator is to remove the water from the maple sap, so removing some of the water as ice is a super simple way to reduce your boiling time.
Tubing Connector for tapping sugar maples
We buy our taps and tubing from Leader Evaporator. The smallest length the tubing comes in is 500′, but don’t fret, its quite inexpensive, about $60 for that much tubing. To buy a lesser amount of tubing locally would cost just as much. We use Tree Saver taps. Buy a bunch of their tubing connectors too, you will need them to tie several taps into one bucket.
In a future sugar maple tree tap video, we’ll connect several trees into one large collection barrel.
Check your buckets every morning, scoop out the ice with a sieve, and then store the sap in a large barrel that is in a cold place packed with snow. The sap has to stay cold or it will spoil. You can tell if you sap has gone bad if it has a milky color to it.
I found a used large stainless steel pot that was probably used to boil clams, and I found a large shallow stainless steel bowl at the dollar store. The idea behind this DIY maple syrup evaporator is the cold sugar maple sap is brought up to a boil in the first large pot, and then it is ladled into the shallow finishing pan to be boiled down into maple syrup.
I strongly suggest buying a digital kitchen thermometer, old style candy thermometers are hard to use with this setup.
This video shows how we improved version of 
