This picture guide goes through the steps I take to boil the sap for making maple syrup. This is the second step in the process of making maple syrup, after collecting the sap, but before the final finishing boil.

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This is part 2 of a 3 part series on how to make your own maple syrup. These are the links to the other articles in this series:

What I Recommend:

I use a turkey fryer to boil sap in for these reasons. These are the supplies you’ll need for sap boiling:

How to Boil Maple Sap for Syrup – Step by Step

The following steps are the easiest way to boil maple sap to make your own maple syrup! The process is actually very straightforward. You just need to boil the sap (which has a sugar content of ~1-3%) until most of the water has evaporated, and the sugar content in the remaining liquid is 66% (“maple syrup”). You will end up with some really, really tasty maple syrup, and as you go along and gain experience, you may decide you want to tweak the process to your liking, but the method shown here is easy and “tried and true”!

I sometimes get the question, “Why don’t you just do all of the boiling on your kitchen stove?” The answer is that, while you could do this, it is generally avoided because of the large amounts of sticky steam that are generated in the sap-boiling process. The other reason is that it takes several hours or more (depending on how much sap you are boiling down) and if you forget about it (and it boils all the way down) there could be a fire risk, which you would want to avoid inside your home!

The following method is the one that I used based on years of experience doing this with my family as a kid over a wood fire and continuing on now into adulthood. I have refined my techniques over the years and in this post I try to go through those techniques, and why I’ve arrived at that way of doing things!

Alright, let’s get started!

How to Boil Maple Syrup – Steps:

  1. Set up a turkey fryer or wood fire in a safe place.
  2. Fill a boiling pot with 5 gallons of sap.
  3. Boil the sap for approximately 4 hours.
  4. When you have about a half gallon left in the pot, finish boiling on a stove.
  5. The syrup is done when it reaches 219°F or 66% sugar content.

Detailed Step by Step Procedure for Boiling Maple Syrup

Step 1: Arrange the Evaporator

Set up your wood fire or turkey fryer in a safe place where it won’t start surrounding brush on fire. I use a boiling kettle (“turkey fryer”) mainly because of the ease of use (instant heat) and better tasting syrup. Wood-burning can make syrup taste smoky, whereas propane burns cleanly – its only byproducts are carbon dioxide and water.  But any source of heat should work as long as you can use it to boil the sap.

Note: See my list of 5 Reasons to Use a Turkey Fryer for Making Maple Syrup.

Step 2: Fill the Pot With 5 Gallons of Sap

Pour 5 gallons of sap into your boiling pot and start the fryer. I often like to start boiling with 2-3 gallons of sap, and once the boiling has started, add a gallon about every hour or so.


In order to increase the surface area of the sap being boiled and therefore increase the rate of evaporation, some people use a cooking pan.



Step 3: Boil the Sap for 4 hrs

Set it at a medium heat and wait for it to start boiling. Once the sap starts to boil, you may need to adjust the heat slightly so that it keeps a nice rolling boil. If it is too hot, it will start to boil over. If it is too low, you won’t see bubbles coming up. Use a stir paddle to stir the sap occasionally. Once a rolling boil has started, adjust the heat so that it remains rolling without a lot of bubbles and without foam completely covering the top surface. The goal here is to dissipate steam, if there are a lot of bubbles on top, they can actually have an insulating effect and increase the amount of time it takes to boil off most of the water. Watch the steam coming off the top and when you have this maximized, that is the temperature you want to remain at.

In the picture below, the sap has been boiling for about 1 hour.


Every now and then skim the foam off of the top using a skimming spoon. Getting rid of the foam will help cut down on the cloudiness of the final product.


Continue to boil down the sap until you have about 1.5″ to 2″ of sap in the bottom of your kettle. This will take about 4-5 hours. This will get your sap to about the 10:1 ratio.


Step 4: Finish the Boiling on a Stove

In the following picture, the sap is nearly done boiling outside, notice the rich dark color of the sap. Soon, we will turn off the burning and bring the sap inside for the final boiling.


Finish boiling the sap to the final sugar content on an indoor stove – for more control.

Step 5: The Syrup is done when it reaches 219° or 66% sugar content

I recommend doing the ‘finishing boil‘ on a stove so that you can keep a closer eye on it as well as to monitor the temperature more closely.

It is not exactly obvious when the syrup is ‘done.’ Technically it is done when it has reached 66% sugar content. You can measure this exactly with a kitchen refractometer – an inexpensive device that looks like a kaleidoscope (about $20) that measures the sugar content of syrup by dripping a few drops onto its viewing slide.

A complete description of the finishing boil and a picture guide on using a refractometer is given in the next article on How to Perfect the Finishing Boil for Maple Syrup.

For answers to some of the more common questions about harvesting and boiling maple sap, check out our most common Frequently Asked Questions!

Tools and Supplies Used:

Check out the “How to Make Maple Syrup Podcast!”

How to Make Your Own Maple Syrup for Less than One Dollar How to Make Maple Syrup!

“What if I invest in a bunch of equipment, and then decide I don’t actually like making Maple Syrup?” In this podcast episode, I give you a super simple (and inexpensive) way to try out making Maple Syrup with almost no investment whatsoever! You will still need access to a Maple Tree (any type is fine) round-about mid-March, as well as a few simple supplies (you probably have them lying around the house…), and then you can try out “Maple-Sugaring” to see if you actually enjoy it! We’ll also talk about how much it actually costs to make your own maple syrup (once you decide to take the plunge). We’ll go through startup costs as well as recurring costs. Download the FREE – How to Make Maple Syrup Quick-Start Guide found here: For more information on the details of what was discussed and links to the equipment I use for boiling Maple Syrup, view the blog posts on these topics: 1. How to Tap Maple Trees for Maple Syrup 2. How to Boil Sap for Maple Syrup 3. How to Perfect the Finishing Boil Ep006 – How to Make Maple Syrup Podcast – How to Make Maple Syrup for Less than One Dollar!
  1. How to Make Your Own Maple Syrup for Less than One Dollar
  2. How to Perfect the Finishing Boil for Maple Syrup
  3. How to Boil Sap for Maple Syrup
  4. How to Tap Maple Trees for Maple Syrup
  5. Identifying Maple Trees, Sugar Content, and Taste