Boiling maple sap in your backyard is not hard – and it’s VERY rewarding! Do it once and you’ll be hooked!

Boiling maple sap is the very last phase of maple sugaring. Have you tried it yet? When my brother in law visited our new home for the first time, he mentioned that we had a bunch of maple trees. He recommended tapping them and I was amazed that we might be able to make our own delicious syrup!

It took a couple years for me to work up the nerve to do it. Once I did, I was amazed! Such a simple and inexpensive thing has yielded rewards for our family for the last 3 years. It has also given us the BEST times together. It was a great success and I’m so glad we did it!

Tapping trees and boiling maple sap takes a long time. However, a little bit of patience yields a yummy reward! There’s nothing like tasting a bit of that hot syrup and realizing that all your effort paid off! Here we will break down the 10 simple steps for boiling down maple syrup in your own backyard.

10 Simple Steps for Boiling Maple Sap

(If you want to go to one comprehensive post that links to each stage of the process, find that here)

  1. Collect sap
  2. Build backyard evaporator
  3. Chop wood to feed the fire
  4. Build a fire in the evaporator
  5. Fill 4″ deep steam table pans with sap
  6. Refill pans and stoke fire every 20 min or so the first few hours
  7. Move stoking and refilling to every 15 min after most of the sap is in the pans
  8. Keep a close eye on it once all the sap is in the pans
  9. As the pans boil down to about halfway full, move sap out of one pan and pour it into others and replace with water
  10. When the syrup is dark and makes tight bubbles, bring inside to finish off in the kitchen

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1. Collect Sap to begin boiling maple sap

The first step in the process of making your own maple syrup is identifying sugar maple trees and gathering the watery sap over a flow period of a couple of weeks in late winter and early spring. I delve more into all of this in a blog post I wrote about collecting sap. I even talk about the amount of sugar in sap and how that affects your finished syrup.

It covers everything you need to know the first year you tap trees and gives links for the next step in the process. It even lets you know what type of sap production you can expect and what trees to tap, like whether or not you can tap a silver maple, a red maple, or a black maple.

Collecting sap can either be done at your own home or a friend or family member’s property. One thing you’ll need to take into account is that when the sap is running hard, you’ll need to empty those buckets often and store them in a cool place until you can boil it down – so make sure your trees are easily accessible!

2. Build a diy backyard evaporator for boiling maple sap

The next step in the process of maple sugaring is boiling it down. Since you cannot do it indoors, you need to have a plan on how to do that outside. You’ll need a heat source and an evaporator pan with a large surface area.

It takes a lot of sap to make maple syrup – about 40 gallons of sap to make 1 gallon of syrup! That means the average amount of water that is evaporated from one gallon of syrup is 39 gallons! That’s a ton of water! If you did this inside your home, you could end up having issues with mold by releasing that much moisture into your air. You could even peel the paint off your walls!

However, there are many ways to boil maple sap outdoors. Lots of people use turkey friers to boil them down, but that does use quite a bit of propane. I chose to build a cinderblock evaporator because we have access to a lot of wood on our property, so that is a great source of free fuel.

I wrote a whole blog post about building a backyard evaporator that details how to use cinder blocks to create an outdoor oven. You simply build a wood fire underneath the stainless steel syrup pans and that open fire boils down the watery sap into delicious maple syrup. It’s the most inexpensive and portable little sugar shack!

evaporator, wood and sap for boiling down maple syrup

3. Chop wood to feed the fire

This part is actually fun and a great workout! Whether you’re getting wood from someone else, or from your own backyard, you’ll need to chop it up so that the logs are small enough to catch quickly and burn hot. We usually cut the logs into chunks about 3-5″ wide and 15-20″ long.

If you’ve never split wood before, here’s a great video that shows you how to do it! We use a splitting maul like this one. It’s such a great way to get a workout and get all your pent up frustration out 🙂

4. Build a fire in the evaporator

The next thing you need to do is to build a fire inside the evaporator. Normally my husband or older son do this. But for our final boil of the season this year, they were both at work. My 12 year old and I started the fire and although it took a while to get going, we had a blazing hot fire after just a little while!

If you haven’t done it a lot, you can click this link to learn how to build a fire. I promise, it’s a great skill to have!

5. Fill pans with maple sap and begin the boiling process

After the fire is hot, I place the 4″ deep steam pans on top and fill them with sap. When we boil down, we usually have 25-45 gallons. I pour enough sap in to fill up those 3 pans, and this normally takes about 8 gallons. We keep a metal strainer nearby so we can pour the sap through that and get out anything larger that is in it like bits of dirt or a blade of grass, etc.

Once the pans are full, it will take some time to get them to a rolling boil. They go through a process of starting to gather tiny bubbles and a little foam on top and steaming. If you keep a hot fire, it will start to boil the sap. From here on out, you’ll want to keep the fire stoked and the pans full. This process normally takes us 8-12 hours depending on the amount of sap we have. We like to stay on top of it so it doesn’t slow down the process.

maple sap
maple sap in pans on evaporator

6. Refill pans and stoke fire every 20 minutes or so for the first few hours

I tend to set a timer for 20 minutes every time I come in from checking the sap. My husband isn’t that precise, but my ADD brain needs reminders! Once the timer goes off, I go out and see if the fire needs to be stoked. You will get the hang of it over time, but you don’t want to get it too screaming hot because it will make the sap foam up and boil over the pans. That’s bad!

So I see if it needs more logs and then I see how full the pans are. I like to keep mine very full so I don’t accidentally boil it down too far. At this point, you’ll also see if there is foam on top of the pans. If there is, you can use your mesh strainer to skim the foam off. We normally hit it against the side of the evaporator to get all the foam out of the strainer. (see video for a demonstration of what this looks like)

Side note…

In the photos I’m going to show, we could not get the fire close enough to the front of the evaporator. As I looked back at the photos from last year, I realized that this year we built the front part of the evaporator inside the structure so it slayed flush against the front. In previous years, we built it outside the evaporator which allowed us to make fire all the way up to the front pan. Because of this, the fire was a little further back and only heated the front pan instead of boiling it, which didn’t cause much evaporation from that one.

Because of that, we used the front one to heat the sap. Then we refilled the back two pans from that warm sap. We only refilled the front pan from the cold sap buckets. This is not what we have done in the past. Usually we just refill all the pans from our cold sap bucket. But because of the way our fire was heating this year, we used the method of warming the sap in the front pan and refilling from there.

boiling sap

7. Move restocking and refilling to every 15 min after most of the sap is in the pans

When the color of the sap begins to turn to a more amber color and it seems to be foaming more, I move my stoking the fire and refilling the pans to every 15 min. I just like to keep a closer eye on it as it gets nearer to the end because I have more to lose if something goes wrong!

Over time you’ll get a hang of how full to fill the pans. It really depends on how raging your fire is. Also, as the sap boils down more and gets a higher sugar content, it tends to foam up more. So I always keep the pans a little less full as the sap boils down more in order to keep it from boiling over once it gets to a really rolling boil.

boiling sap in pans

8. Keep a close eye on it once all the sap is in the pans

Once all the sap is in the pans and your buckets are empty, you’ll want to keep an even closer eye on it. You’ll see the sap get darker as the sugar in it caramelizes and the water boils off of it.

We had a friend who forgot about it at this point and ended up burning about 2 gallons of syrup. That is devastating after all that work! So stay close by and keep an eye on it to make sure the fire stays hot, but not hot enough to make that liquid gold boil over!

As a side note, I had to leave for an appointment and was gone for a few hours, so I missed the stage between the picture above and the picture below. It looked pretty much the same as the one above but darker brown 🙂

9. As the pans boil down to about halfway full, begin to move maple sap out of one pan and pour it into others and replace with water

I start to combine my syrup once the pans get down to about halfway full. I start with the front pan and pour it evenly between the other two. Then we put water in that front pan and put it back in place. The water keeps the pan from getting damaged by being empty over a hot fire.

In previous years, we’ve then combined the other two pans when they got to about halfway. This year, however, we decided that we wanted to have more surface area evaporating water because we were tired 🙂 So we kept both of them on the fire and just watched them VERY closely.

The reason you’d keep combining them into one is that there’s less of a chance to burn it if there’s more sap and syrup in one pan. The more it’s spread out, the more opportunity there is for you to get distracted and burn that precious liquid.

cooking maple syrup

10. When the maple syrup is dark and makes tight bubbles, bring inside to finish off in the kitchen

Once the maple syrup is dark, you’ll see the bubbles begin to change. You see in the pictures that the bubbles tend to clump together in groups and make tight, smaller bubbles. This tells you that the water content has drastically decreased and the syrup density has increased.

At this point, it’s a good idea to ladle it out of the evaporator pan and run it through cheesecloth to strain any debris out of it. Oftentimes there will be sugar sand at the bottom of the pan. You don’t want that in your syrup! So strain it out.

You are SO close to getting your pure maple syrup! In this blog post, we talked about boiling maple sap to take 40 gallons of sap and making a gallon of maple syrup. But after this step, you’ll need to finish the maple syrup on the stovetop inside.

The final stages in the process of making maple syrup are detailed and can be the make it or break it step! You’ll need to put the syrup in a large pot on your stove and watch closely, using a candy thermometer or digital thermometer to make sure it hits the proper temperature. Find detailed directions on how to get to finished syrup in this blog post.

maple syrup boiling
pouring maple syrup through cheesecloth

Many times I don’t finish it off in the kitchen right away. I will put the pot into the fridge and complete the next day. I’ve even put it into our deep freezer to store it until the next time we boil down sap that season so that I can finish them all off at once.

Homemade maple syrup is such a treat! Whether you have small batches and end of with just a quart of maple syrup, or gallons and gallons, I think you’ll love it! Try it next year! When you look at those glass bottles full of sweet, sticky syrup with an intense maple flavor, I think you’ll agree that it’s the best thing to do when you’re waiting for spring to arrive!

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sap in pans and pouring maple syrup through cheesecloth

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