Density of Maple Syrup

The density of maple syrup is often misunderstood by consumers and probably the one thing I get asked the most after the grades of maple syrup. We put a lot of weight on flavor and grade, but checking for density is just as important.

What is Density

Simply put, density is how much mass can be crammed together to take up space. If you had 2 bags of the same size and one bag was heavier than the other, the heavier bag is more dense. We can go through the scientific steps to figure out the density of maple syrup or just take the word of scientists. Maple syrup has a density of 1.37 grams per milliliter, heavier than water, milk and corn syrup but not as dense as honey.

Checking the Density of Maple Syrup

When maple syrup is made, the sugarmaker wants to draw the syrup off the evaporator at the correct density.  When the temperature of the syrup reaches 7 degrees above the boiling point of water, it has reached the correct thickness.  A hydrometer is also uschecking the density of maple syruped to confirm that the maple syrup is at the legal standard.

At the Carman Brook Farm we store the syrup we made during the production season in barrels to be bottled throughout the year.  We pump a barrel into our canning unit and reheat that syrup to about 140 degrees Fahrenheit to make our density check.  Our hot water jacket syrup canner heats 40 gallons of syrup from the outside to the inside. To ensure tmaple syrup density charthat all of the syrup is the same temperature, we spend several minutes stirring the maple syrup.

Using a stainless cup and hydrometer, a sample of syrup is tested. Since the syrup is not at the high temperature that was necessary to produce it earlier in the spring, we use a sliding chart. The chart adjusts what the brix should be, when the syrup is at a specific temperature.  The shot to the left is my trusty and very old and well used chart.  I’ve been given newer ones, but this one is my favorite.  I’ll have to ask that you please disregard all the smudge marks.

Official Vermont Density of Maple Syrup

The Vermont Maple Products Regulations includes a standard for maple syrup density. In section 8 of the regulations the following paragraph is what the state mandates as a minimum standard. The regulations apply to all the grades of maple syrup. I’ve been told that the darker syrup is thicker, when it actually isn’t any thicker than the light syrup.  I think that the flavor of darker syrup sticks to your taste buds a little longer, giving a thicker impression.

“All grades of packaged maple syrup shall have a minimum density matching its temperature, as indicated on the following chart, which is equivalent to 36 degrees Baume Modulus 145 or 66.9 degrees Brix at 60 degrees Fahrenheit on instruments calibrated at 60 degrees Fahrenheit or other equivalent measurement of density, as determined by the Secretary of Agriculture.”


We keep production records for every batch of syrup that is canned. The production records contain the density readings.  I’ve summed it all up in about 500 words in this post, but its actually a lengthy and tedious process.  There are a lot of details to taking an accurate density reading and a lot of patience is required.  We take the reading at least twice.  If another person is in the sugarhouse, we’ll take each person’s readings and compare notes.

Dangers of Density Testing

After we took these pictures, I climbed back up to take a real density reading. The picture taking was distracting as Jon was having a lot of fun snapping photos of me and taking “action” shots. Sadly, while coming down off the ladder, I fell and broke my foot. I had started working on this post about a month ago.  I really dragged my feet on this topic, no pun intended. With the extra couch time I’m getting I thought I’d finish it up and share. I’ll be more than available to answer your questions and comments in the following weeks.

Comments 11

  1. OH NO! I am so sorry to hear about your foot! Dang it. Hope you mend well.
    This would explain why most of the syrups in NY are so thin?
    Also does the density add to the flavor?
    We have come to the conclusion lack of full boil adds to thinness and taste?

    1. Post

      Thanks, Gina! I’m pretty certain that with the new maple laws all states are using the same standards. You are right, the longer the syrup boils the thicker it gets. Taste only has to do with the sap and what grade of syrup that sap produces.

  2. Oh, Karen, I’m so sorry about your foot! I will be praying for a quick recovery! I enjoy learning about syrup making through your newsletters. Take care!

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      Thank you, Andrea, I appreciate your good thoughts. My 2017 goals are to write more posts and share information. It makes it easier to know that the posts are read and appreciated.

  3. I wish I could find denser specialty maple syrup sold somewhere. Used as an ice cream topping, regular syrup is too runny. In fact, I think the ideal would be one you need to warm up slightly to pour, like the chocolate syrup we get (not Hershey’s!) for ice cream. I imagine if a syrup variety was dense as honey then like honey it wouldn’t mold because the sugar concentration would be too high.

    1. Post

      It sounds like you know your ice cream toppings!! Unfortunately, the maple syrup laws do state a density that syrup needs to comply for sale. If you want thicker syrup, you could just boil the syrup until it thickened up a few degrees. I wouldn’t go higher than 225 degrees F. After that you’ll get a thick blob that you wouldn’t be able to scoop with a spoon.

  4. On the science front, you reminded or informed us with an explanation of density but didn’t explain the other interesting aspect of the collection process, which is implied in these sentences:

    “When maple syrup is made, the sugarmaker wants to draw the syrup off the evaporator at the correct density. When the temperature of the syrup reaches 7 degrees above the boiling point of water, it has reached the correct thickness.”

    That is, it’s not about heating the syrup to a certain temperature, as you might, for example, heat water to 50° C, it’s about what stable maximum temperature it reaches. This changes according to the density and thus the temperature in the evaporator can be used to gauge the density of the syrup without having to extract some and do a direct measurement.

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      John, would you like a job writing for me??!! You are right. I think when I wrote this, I was thinking that the boiling process would make another post and then link them.

      We do boil to the density of the syrup on the hydrometer as you explain in your comment. No, we aren’t boiling so much to a temperature, as we would boil water.

  5. CB, Great site. Hope your foot is all better by now (2/19). I’ve been a beginning syrup maker for 3 years now. Boiling the sap as we speak. Always went by temperature and eyeball before. This year I broke down and bought a hydrometer. Look out Mr. Baume’ here I come!
    Mark H.

  6. I have a hydrometer my question is when my syrup reaches the hot line on my hydrometer am i truley done or do i have to check the chart or anything else or can i filter an jar right then like i have been doing? Still new an trying to learn this method to have a more consistsnt product. Thank you for your help

    1. Post

      Hi Jason; I use the chart for bottling syrup, since it isn’t heated to the same temperature as when syrup is produced. I hope that answered your question. There is a lot of information available online and with the Vermont Department of Agriculture. There are also a few handouts/booklets available.

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