How to Make Your Own Maple Syrup – Part 2: Boiling Down the Sap

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If you have a few backyard maple trees and you live in a climate where it’s below freezing at night and above freezing during the day time, then it’s really quite simple to make your own maple syrup and boil down the sap into delicious syrup that you can drizzle over pancakes or use in cooking and baking. 

In my last post I talked about all of the things involved in preparing for sugaring off, including: identifying trees, choosing the right time and place to tap the trees, drilling the hole, and setting up the taps and collection containers for the sap. If you haven’t read that post already, you can find it here: How to Make Homemade Maple Syrup – Part 1: Tapping Your Trees.

Today, we’ll talk about the rest of the steps we need to take in order to be able to get from watery sap to sweet maple syrup. 

Collecting the Sap

The sap will flow the best on sunny days when the temperatures the night before were below freezing and the day time temperatures are warming up above freezing into the 40-50 degree range, so those are the days when it’s definitely a good idea to check on your sap collection containers. 

Depending on the weather, you might find that you have hardly any sap on some days when you check, but then on other days you might end up with so much sap that it’s close to overflowing your containers. 

Any days when the weather warms up above freezing and the sun is shining, it’s a good idea to check to see if you have any sap because if the sap sits for too long in the collection bucket then it can start to spoil. Sap is kind of like milk in way rather than like water. If your sap looks really cloudy when you go to check on it then it might have gone sour, and it’s probably best to just toss it and wash out your container. 

So, if it’s a really cold day (as cold as the temperature inside your refrigerator or colder) then it’s fine to leave the sap and wait a day or two to check on it. (I’ve definitely done this on days when it’s bitterly cold outside and I didn’t feel like trudging through the snow to check on the sap.) But if the weather starts warming up then you’ll want to bring the sap inside and either boil it down right away or keep it in the fridge until you’re ready to use it. 

Storing the Sap

When you’re making your own maple syrup on a smaller scale with just a few backyard trees, it isn’t always practical to boil down the sap as soon as you collect it from the trees. If you only have a couple of maple trees and you end up getting just a small amount of sap on one day, it doesn’t really make sense to boil down that small amount because it would take a couple of hours of boiling for a very small amount of syrup. 

What usually works better for small-scale maple syrup makers is to collect the sap over a period of several days and then boil it all down at once. Sap should keep fine in the refrigerator for up to a week, so you can collect it and store it until you have enough sap to make it worth boiling down. 

This also allows you to boil down the sap at a day and time that’s convenient for your schedule. So, if you have a regular weekday job, you could wait until the weekend to boil down your sap when you have more free time. 

A lot of the time spend boiling down the sap is hands-off time where you can just leave the pot boiling and check on it every once in a while, but depending on how much sap you have, it might need to boil down for a several hours, so you’ll want to pick a day when you can be home for that period of time. 

Where to Boil the Sap

Big sugar houses have special evaporators that they use for boiling down the sap, and there are smaller evaporators that you can get for personal use too, but if you just have a few maple trees in your backyard, it’s probably not going to be very practical to invest in something like that. 

A lot of people say that it’s best to boil down the sap outside because of the amount of steam that it creates, and if you look online there are all sorts of different things people have come up with to create outdoor sap boiling stations. For me, though, I haven’t had any problems with boiling down my sap inside the house.

Since I only have three maple trees, I don’t have huge amounts of sap to boil down at once, and even though it does create some steam, I haven’t found it to be enough to the point where it causes any problems. The air inside my house is always so dry in the winter time that the extra humidity is welcome, and if I really needed to I could turn on the vent above the stove to get rid of some of the extra steam. 

Boiling down the sap inside the house in pots and pans on the stove is definitely more convenient when you’re making maple syrup on a small scale, and it’s nice to be able to do other things around the house or in the kitchen while it boils and not have to keep going outside to check on the sap. 

How Much Syrup Should You Expect to Get?

Different types of maple trees have different amounts of sugar in the sap, but in general, there a 40 to 1 ratio of sap to syrup. So, if you have 40 gallons of sap, you’ll end up with about 1 gallon of maple syrup. I know that that sounds like a huge difference and a daunting amount of sap needed to produce maple syrup, and it is. That’s part of the reason why pure maple syrup can be so expensive to buy. But it’s also not quite as disheartening as it seems at first when you see how much sap your trees can produce at the height of the season. 

Depending on how many trees you tap and on the weather, you might end up with some days where you get several gallons of sap just in one day. So even if you’re making your own maple syrup on a small scale, it’s possible to still get a decent amount of syrup during the season.

The sap production will vary depending on your individual trees and the weather, but this is an estimate of the amount of syrup you can reasonably expect to get based on the amount of sap you have:

40 gallons of sap = 1 gallon of syrup

20 gallons of sap = 1/2 gallon of syrup

10 gallons of sap = 1 quart of syrup

5 gallons of sap = 1 pint of syrup

Boiling Down the Sap: Step by Step

Step 1: Select Your Pots and Pans

The amount of sap you have will determine what size pots or pans you need, of course, but I usually like to put my sap in the biggest pans possible and spread it out between a couple of different pans because it will boil down faster that way. Rather than having one or two pans filled to the brim with sap, I like to have a pan on each burner boiling down so that each pan has less sap in it and the boiling process won’t take quite as long. 

Step 2: Filter the Sap

When you collect the sap from outside, you’ll often find little bits of dirt or other sediment floating in the sap, so I always start by filtering my sap as I’m pouring it into my pans. To do this, I line a strainer with a looseleaf tea filter  and pour the sap through it and into the pan. The tea filters work perfectly to let the sap pour through while filtering out any dirt or sediment. 

Step 3: Boil Down the Sap

This is the step that takes the longest, but it’s also the part where you can mostly just leave the sap boiling on the stove and just check on it once in awhile. Depending on how much sap you have and how full your pans are, this could take anywhere from a couple of hours to a good portion of the day. If you only have a gallon or two of sap and you spread it out between several pans, it might only take 2-3 hours to boil down. But if you have a larger amount of sap it could take longer.

During this stage, you don’t really need to do anything other than just check on the sap occasionally to make sure it’s still boiling and isn’t thickening up yet and getting close to syrup. 

Step 4: Finish Off the Boil

When your sap starts to get thicker and changes to a darker color, it’s getting closer to the syrup stage. This is the part where it’s a good idea to stay with it to make sure it doesn’t boil down too much. Once you start getting close to the syrup stage, it can go pretty quickly, and it’s easy to end up letting it go too far.

There have been several times I’ve let the sap boil too much and ended up with maple sugar instead (which is still delicious) and a couple of times I’ve made almost a maple caramel. It was thicker than syrup but not quite sugar yet, and it was also just as delicious, but it still wasn’t the syrup texture that I was aiming for. 

Knowing when the syrup is done is a little bit trickier too if you are working with smaller amounts of sap, because if you only have a little bit of liquid left in the pan at the end of the boil, it will change stages much more quickly and you can go from thin sap to maple sugar in just a few minutes. 

How to Tell When the Syrup is Done

There are a couple of ways that you can tell when the sap has boiled down into syrup. Most professional syrup makers use a hydrometer to measure the amount of sugar in the syrup (and when it reaches 66.9% it is syrup), but since most of us amateur syrup-makers probably don’t happen to have a hydrometer at home, we’ll stick to the other more accessible methods. 

Another way to test to see if the syrup is done is to use a candy thermometer. The syrup will be done when the temperature reaches 7.5 degrees above the boiling point of water. So, if water boils at 212 degrees at the altitude where you are, then your sap will have reached the syrup stage once it gets to 219.5 degrees. 

And if you don’t have a candy thermometer (or if yours is broken like mine is and you haven’t gotten a replacement one yet) you can also use what is called the “spoon test” to check the old-fashioned way to see if your syrup is done. To do this, you put a spoon into the syrup and watch to see how the syrup drips as it runs off of the spoon. If it drips off in individual drops that look like water then it’s still too thin and it hasn’t reached the syrup stage yet. But if it “sheets” off the spoon and runs off in a continuous stream, then it’s done. You’ll also notice that it tends to stick to the spoon a bit more rather than running cleanly off of the spoon. This video helps to give a visual of what the process looks like as the sap changes to reach the syrup stage. 

It can be a little bit deceiving when you look at the sap because it looks like it is still a bit too runny to be syrup, but as it cools it will thicken up a bit more. There have been times when I’ve thought it was too runny and let it boil down longer, but then after it cooled it was more like a honey or molasses texture rather than syrup. Once you’ve boiled down the sap a few times, though, you get more used to how it should look and feel when it has reached the syrup stage. 

And when in doubt, I usually tend to prefer to boil down the sap a bit too long and end up with maple sugar because that is still perfectly edible and will keep well for a long time. If you don’t quite reach the syrup stage and you end up with a watery syrup that hasn’t boiled down long enough, it will still taste decent, but it won’t be as good as maple syrup and it will be more likely to spoil faster because of the higher water content. 

Step 5: Filter the Finished Syrup

Once your sap has reached the syrup stage, the last step before you bottle it up is to filter the syrup one more time. This step is semi-optional. What I mean by that is that it’s ideal to filter the syrup but not absolutely necessary if you don’t mind not having a perfectly smooth texture. 

As the sap is boiling down into syrup you can end up with what is called “maple sand” even if you filtered the sap before boiling it. This maple sand isn’t dirt – it’s minerals that have concentrated into deposits that can leave a small amount of gritty crystals in the syrup. So, if you don’t filter out the maple sand, you might find that you have a little bit of gritty crystals that gather at the bottom of the jar. 

If you want a nice silky smooth texture throughout your syrup, then it’s important to filter the finished syrup with a maple syrup filter like these ones. But if you’re making the syrup just for your own use at home and you don’t mind having a bit of maple sand at the bottom of the jar, then you can decide to skip this step if you want. (This is what I usually do because the maple sand doesn’t bother me.)

Storing the Syrup

There are several different options for storing your syrup. I personally like to use glass containers because I like to be able to see the different colors of the different grades of syrup. At the beginning of the season, you’ll have syrup that is very light in color and subtle in maple flavor, and as the season progresses, you’ll notice the syrup become darker and stronger in maple flavor. (And when the weather really warms up and buds start forming on the trees, it’s time to stop collecting sap because the syrup made from that late sap will be bitter in flavor.)

You can use glass containers specifically designed for maple syrup like these ones. Or you can also use regular glass mason jars too. And depending on how much syrup you make and how long you want to keep it for, you can store it in a couple of different ways. 

If you’re making smaller amounts of maple syrup and you think you’ll probably end up using it all within a couple of months, then you can just store your syrup in the refrigerator. If you want to keep your syrup for much longer, though, or if you don’t want to have to take up room in your fridge to store it, then another option is to can the syrup so that it will store well in the pantry. This article has a good explanation of how to can syrup for long-term storage. 

And now all that’s left to do at this point is to make some pancakes or waffles or whatever your favorite bread or baked good might be and enjoy smothering it with your own homemade maple syrup!

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The information in this post is not to be taken as medical advice and is not intended to diagnose or treat any disease.