In this article, we discuss the “Jone’s Rule of 86.” How it came into being, how you can use it to make Maple Syrup, and why it has been superceded by the “Jone’s Rule of 87.”

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Making Your Own Maple Syrup

For detailed instructions on how to tap maple trees, boil maple sap, and perform the maple syrup finishing boil, check out these articles:

Making Maple Syrup – Part 1 – How to Tap Maple Trees for Sap
Making Maple Syrup – Part 2 – How to Boil Maple Sap
Making Maple Syrup – Part 3 – How to Perfect the Finishing Boil

01-Maple-Syrup-Boiling-Turkey-Fryer

A simple and efficient method to get started making Maple Syrup is using an outdoor propane boiler (commonly called a ‘turkey fryer’).

The Jone’s Rule of 86

The Jone’s Rule of 86 is a simple equation that is used for determining how many gallons of Maple sap you will need to boil down in order to achieve 1 gallon of Maple Syrup. 

This rule is named after Charles Howland Jones, a researcher at the University of Vermont who published a paper with J. L. Bradlee in 1933 called “The Carbohydrate Contents of the Maple Tree.” The details of which were made clear to me in an old publication called the Maple Sirup Producers Manual (Willits and Hills, 1938) on page 48.

The equation is as follows:

a = 86/X

where a represents the number of gallons of sap you will need to make 1 gallon of Maple Syrup, and X is the sugar content of your sap (expressed in %).

For example, if the sugar content of your sap is 2%, then the equation would look like this:

a = 86/2 = 43

You will need to boil down 43 gallons of sap in order to end up with 1 gallon of Maple Syrup.

What is the Sugar Content of Maple Sap?

The sugar content of maple sap is usually expressed in terms of °Brix, which is the % sugar content of an aqueous solution based on mass.

Sugar maple trees tend to have the highest sugar content, so often the ratio of sap to syrup for a sugar maple is on the order of 32:1 or so, at least in my experience. If you don’t mind ‘watery’ syrup, then you can get away with less boiling, so you end up with a higher yield, like 20:1.

Type of Maple TreeSugar Conc. of Sap (%)Ratio of Sap/Syrup
Sugar Maple4.519:1
Red Maple4.121:1
Amur Maple3.922:1
Silver Maple3.426:1
Box Elder2.535:1

What is the Sugar Content of Maple Syrup?

The sugar content of maple syrup is 66% by mass, and 87% by volume.

How do you Calculate the Sugar Content of Maple Sap From the Ratio of Sap to Syrup?

There seems to be a lot of confusion regarding how the ratio of sap-to-syrup can be used to determine the sugar content of your sap. 

The confusion comes from the fact that Brix is a percentage of mass-to-mass, whereas Sugar Content is a percentage of mass-to-volume. Syrup at 66°Brix has 66 grams of sucrose in a 100 gram sample of syrup, but it has 87 grams of sucrose in 100 mL of syrup.

For small amounts of sugar in a solution (like sap), the Brix and Sugar Content are nearly the same. However, as the concentration of sugar increases, the Brix value and the Sugar Content values begin to diverge (see the graph below).

Maple-Syrup-Sugar-Content-Vs-Brix-Sap-PracticalMechanic

This table shows the Brix value and the corresponding Sugar Content % for lower Brix values (typical of sap, e.g. 3°Br)) as well as higher values (typical of syrup, e.g. 66°Br) (equation from wikipedia, sg values from Table 109, NBS Circular 440):

Brix
Grams of Sucrose per 100 mL of Syrup
0 0.0
1 1.0
2 2.0
3 3.0
4 4.1
5 5.1
10 10.4
15 15.9
40 47.1
60 77.2
64 83.9
65 85.6
66 87.3
67 89.0
68 90.8
69 92.6

Note that the sugar content by volume is about 87 for a Brix value of 66.

By the way, the “Rule of 86” applied back when the standard Brix value of Maple syrup was 65.5°Brix. Now that standard maple syrup is 66°Brix (66.9°Brix in some states), the value should now be the “Rule of 87.”

For sap, the percent of sugar (weight to volume) is small (typically 1-5%), so Brix and Percent of Sugar-to-Volume are nearly the same. Standard density maple syrup has a Brix value of 66°Brix, which corresponds to 87.2% solids as sugar.

The following table shows how many gallons of sap are required to make 1 gallon of syrup for various sap sugar concentrations.

Sap Sugar Conc (%) Ratio
Gallons of Sap to Make 1 Gallon of Syrup
0.0
0.5 174:1 174
1.0 87:1 87
1.5 58:1 58
2.0 44:1 44
2.5 35:1 35
3.0 29:1 29
3.5 25:1 25
4.0 22:1 22
4.5 19:1 19
5.0 17:1 17
5.5 16:1 16
 
 

Conclusion

I hope you found this information helpful! For more information on Making Maple Syrup and to download my free “How to Make Maple Syrup Cheat Sheet,” visit the Maple Syrup Homepage.


Detailed Picture Guides on How to Make Maple Syrup at Home

For detailed instructions on how to tap maple trees, boil maple sap, and perform the maple syrup finishing boil, check out these articles:

Making Maple Syrup – Part 1 – How to Tap Maple Trees for Sap
Making Maple Syrup – Part 2 – How to Boil Maple Sap
Making Maple Syrup – Part 3 – How to Perfect the Finishing Boil

Listen to further discussion on this post on the Podcast:

What is the "Jones Rule of 86"? And how can you use it to make better Maple Syrup? How to Make Maple Syrup!

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What is Reverse Osmosis and Should I Be Using it To Make My Maple Syrup? How to Make Maple Syrup!

In this episode, we talk about why all the big Maple Syrup producers use Reverse Osmosis to make their Maple Syrup. We then answer the question, what is reverse osmosis? Is this something that I can use as a small-time homemade Maple Syrup maker? We answer questions like: Why is Reverse Osmosis helpful? How much does a system cost? What are the downsides to using Reverse Osmosis in Maple Syrup production? And why do some people refuse to use RO? We finish up by talking about the pros and cons for RO and how to get started in case you are interested in trying out Reverse Osmosis for yourself. The following are some of the links mentioned in this podcast: I’d love to hear from you, leave me a voicemail! (I may include snippets in a future episode!) https://anchor.fm/how-to-make-maple-syrup/message Leave a review for this podcast, it helps get the word out! – Go to the following link, scroll down to “Ratings and Reviews,” Tap “Write a Review” at the bottom of the page: https://podcasts.apple.com/us/podcast/how-to-make-maple-syrup/id1596149713 My recommended Maple Sugaring Supplies List as well as Free resources and eBooks on making Maple Syrup https://practicalmechanic.com/MapleSyrupResources Buy a fully functional Reverse Osmosis system from these guys: https://www.therobucket.com/ Plans you can use to build your own DIY Reverse Osmosis system, courtesy of Michelle and Bill at Souly Rested: https://soulyrested.com/ro/ Ep013 – Episode 013
  1. What is Reverse Osmosis and Should I Be Using it To Make My Maple Syrup?
  2. What is the Maillard Reaction? And How Can I Use it to Make Better Tasting Maple Syrup?
  3. Does Tapping Maple Trees Harm Them?
  4. How to Make Crystal Clear Maple Syrup
  5. The Million Dollar Maple Syrup Heist of 2012!