Making a maple syrup evaporator to boil down maple sap doesn’t need to be costly and cause storage issues! Our homemade maple syrup evaporator is inexpensive and breaks down easily.
What is a Maple Syrup Evaporator?
A maple syrup evaporator is a specialized equipment used in the production of maple syrup. It usually consists of a large flat pan designed to efficiently evaporate water from maple sap, leaving behind the sweet treat we know as pure maple syrup.
The process involves heating maple sap to its boiling point and keeping it there over a long time. As it is boiling the gallons of sap, the water evaporates and the sugar content increases. When the sap level goes down, more maple sap is poured in until all the sap that has been collected is in the reservoir pan.
Once the liquid reaches a specific temperature, it’s tested to see if it has the correct sugar content. Then it’s bottled and that’s what we know as maple syrup!
What type of evaporators can you buy?
If you don’t want to make a maple syrup evaporator, there are lots of varieties you can buy. The Smoky Lake continuous flow evaporator is the top dog in the industry. If you want to have a maple sugaring business, you might want to spend $6,500 on one. I don’t 🙂
Then you take a step down and while ones like this are expensive, they are super efficient and designed for maximum performance if you want to make a lot of maple syrup. It has a stainless welded preheater pan to bring the new sap to temperature slowly. There’s an airtight cast iron door to be super efficient with your wood burning. It’s amazing, but it’s also over $1500 and way out of my price range, as I am a hobbyist maple syrup producer.
Another option for a backyard sugar maker is Vermont Evaporator Company’s Sapling Evaporator variety. It’s a steel barrel design with two flat sections. One is a warming pan for new sap. The other is an evaporator pan with a big surface area for evaporating out as much water as possible. It has a front door that keeps the wood fire burning efficiently. This sapling unit is super cool, but still $1500. Ouch
Why would you make your own backyard maple syrup evaporator?
I love to try new things, but I certainly didn’t need an ideal evaporator with a huge price tag to get the job done. I knew I didn’t want to take my sap somewhere – I wanted to do it in my own backyard. Also, I didn’t want to have to store one of those huge maple syrup evaporators the other 11 months of the year when it wasn’t in use.
I needed something that could to contain the open fire. It also had to have a pan for the maple sap that was big enough to evaporate and condense down into hot syrup. I also wanted an exhaust stack to try to keep the smoke out of the syrup. Lastly it had to be portable and be able to be out of the way when it wasn’t in use.
This is what I came up with. It evolved over the years, so I thought I’d break it down into our 1st year of use and our 2nd year and beyond.
Maple Sap Steam Evaporator Year 1:
When we began to make maple syrup the first year, we felt like we were spending a lot of money. The taps, cinderblocks, and stove pipe added up. So we didn’t want to spend more money on the stainless steel pans like you’d use in a buffet line. In the end I don’t think I regretted it, but it definitely made for a unique, smokey flavored maple syrup! Honestly I cried a little the first time I tasted it because I wasn’t expecting that smokiness, but in the end I kind of loved it!
We put old oven grates on the top and built the evaporator to fit the specifications of the grates. That sounds fancy, but really we just laid the first row of cinderblocks down and then made sure the grates fit securely on them before we began to build up the sides. Here’s what our maple syrup evaporator looked like the first time around.
We tried to choose a flat pan to put on top of the grate that had a very large surface area in order to allow for the most evaporation. Remember, you’re boiling off 39 gallons of water for every gallon of syrup, so you need to evaporate so much water from the maple sap!
It’s a good idea to have a small stainless syrup pan with handles to help you pour it. We used a cast iron pan, a large flat pan from a friend, and another single pan that we found at Salvation Army. It wasn’t high quality, but it did the job the first year and we were so glad we did it!
Maple Sap Steam Evaporator Year 2:
Last year, I bit the bullet and bought 4″ deep full size steam stainless steel pans. I found them on sale for about $15 each, so it was inexpensive to add them. Unfortunately, it looks like the price I see right now is almost double – $28 each. I would probably recommend searching the restaurant supply stores because you may find them less expensive there. The evaporator pan made a HUGE difference in our syrup operation this year!
The biggest difference by adding the evaporator pan was that the entire surface area of the oven was completely covered. After feeding the fire, we closed up the feeding hole. This way, every bit of smoke escaped through the stove pipe, completely removing the smokey flavor from the maple syrup. The syrup this past year was unbelievable!!
Supplies to build Maple Syrup Evaporator:
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Full Size 4″ Steam Pans – you’ll use these as the evaporator pans to give you as much surface area as possible to allow for the fastest evaporation of water. Alternately, you can use a set of pans on top of a grate or rack.
Cinder Blocks (about 25) – some people think you need something like fire brick to make this. While concrete blocks won’t last forever, they will definitely give you many years of pleasurable use before they break down!
6″ Duct Pipe – I use this for our exhaust stack. It allows the smoke to be redirected away from the syrup
90 degree Pipe Elbow
Wire to Attach pipe
Extra bricks or blocks to cover opening
How to build a maple syrup evaporator:
This is not a huge engineering feat to build and it really doesn’t even have any sort of plans. This is the way we do the process.
The first step is to try to find really level ground. If you’re even off an inch from side to side, you’re going to have boiling maple sap that is not evenly distributed in the pans. Once you find a fairly level spot, lay your cinder blocks in a U shape that is the width of the pans. Set your pan on top of them to make sure the lip of the pan fits snugly inside the U shape with no extra room.
Now, level that first row of cinderblocks before you begin to build it up. We keep some thin stones from our waterfall feature to help us in the leveling process. Once that bottom row is fully level, you can begin building!
The next step is to place the second row of concrete blocks on top of the first. Do you remember when you built with Lego and you had to overlap the bricks so the seams didn’t match up to make the walls of your house strong? You have to do the same thing here. We did purchase some single cinder blocks, as well as doubles so we could do the jigsaw puzzle and see what worked.
Make the second row level before you top it off with the last row. Now add the last row. This is where you’ll place your chimney. I usually try to use a single cement block on this row so I can turn it sideways and make an open hole to place the 90 degree elbow and pipe through. Once I get to this level, I place the empty pans inside to make sure I have a nice tight fit. If it’s even an inch or two too big, the full pans can fall into the fire below and waste all your hard work. So just fit them in snugly and they will be great!
Attach the stove pipe on to the cement block with wire. We’ve done it by just attaching it to the cement blocks the first time around. The second year, my husband found some pieces of metal around our garage that had holes in them where he threaded the wire. This is not necessary if you loop it around the pipe and secure it well to the cement blocks.
Create a way to stop the heat from getting out by placing blocks or bricks by the opening. We just kept heat pads nearby. Then we use them to move the hot bricks each time we needed to feed the fire. That way the opening was blocked off and kept all that heat inside
And there you have it. A complete evaporator consisting of a place to burn wood, a chimney, and evaporator pans! Now that you’ve got your final product, stock up on logs and get ready to go! I’ll go over the boiling down method in another post! Check it out here!
We made a YouTube video showing the step by step process as we built this in Feb 2022 for our 3rd year of maple sugaring! Watch it here!
Once you have some screaming hot coals, you can even take your hot dog forks out and make dinner over the fire. Or you can do what we did and roast marshmallows over the fire. What a sweet treat!
How to store the Maple Syrup Evaporator:
We break our evaporator down and pile the cement blocks up on the unseen side of our house, or inside our garage. The 90 degree elbow, the pipe, and the wire are stored all together with it, so it’s ready to go next year!
We wash the steam pans and store those down in our basement with all our food safe collection buckets and taps and tubing. Even though we wash all those before we put them away, we wash everything again before we set it all up just to make sure it doesn’t have any bacteria in it.
Does this ruin the grass?
Yup. Having a fireplace in the middle of your grass definitely kills an entire rectangular spot in the grass. We just raked all the ash out of it and immediately planted grass and it was great by the summer. Of course, we didn’t do it in our main area, but we did want to make sure it was super close to the house so we could go in and out throughout the day as we worked.