Can invert sugar syrup be used in place of corn syrup?

So ask readers Mari and Lisa. I live for this sort of stuff, so let’s get into it. First, let’s define a few terms. Corm syrup is something most of us are very familiar with. It’s a syrup made from corn endosperm (starch) that has been exposed to enzymes which break the long chain starch molecules down into short sugars that human tongues can taste. The result of all this molecule-breaking (hydrolysis) is a soup of roughly 15% glucose (one of the very simplest of sugars), 10% maltose (two glucose molecules bonded together) and 55% longer sugars. These longer sugars blunt the sweetness of corn syrup simply because we don’t have taste receptors for all of them. They also give it thickness. The last 20% is water.

Invert syrup is nothing more complicated than table sugar (sucrose) and water, heated with an acid added to it, typically cream of tartar, citric acid or even lemon juice. The addition of acid causes many of the sucrose molecules to split in two, into their component sugars: glucose and fructose. Invert syrups vary widely in how much water they contain. Some are as high as 50% water, but the most useful are the thicker ones which are boiled to the thread or soft ball stage, about 235-240 degrees Fahrenheit. At that point they’re between 15% and 20% water, about the same as corn syrup.

Can one be substituted for the other? The answer is yes, depending on the application. Corn syrup and thread-stage invert syrup have similar viscosities. They’re both smooth, so they’ll add sweetness to a recipe without the grit of crystal sugar. They’re also both good at inhibiting crystallization of sugar syrups, as their molecules — small or large — get between sucrose molecules, preventing them from stacking up on one another like LEGOs and forming crystals. Pastry chefs like this function a whole lot, which is why so many icing, candy, toffee and fudge recipes call for corn syrup. It helps keep these preparations from getting either grainy or so stiff that they shatter on a cake or in the mouth. A lot of ice cream makers also like a little syrup in the mix, since it performs the same function with ice crystals as it does with sucrose crystals, and thus keeps ice cream smooth.

Corn syrup and invert sugar syrup are roughly equivalent at crystal inhibition. Corn syrup is generally more effective at the job since there’s really nothing in it that will crystallize…the glucose, the maltose or the long chain sugars. Invert sugar isn’t as effective because even after the heat and acid treatment it’s still well over half sucrose. Still it’s close enough for jazz in a typical icing or batch of fudge.

The real problem with substituting invert sugar for corn syrup is the sweetness level. Corn syrup was originally marketed as a replacement for molasses, which is sweet, but not as sweet as a sucrose syrup. Interestingly, in the 60’s food scientists finally figured out how to create a corn syrup that was equivalent in sweetness to table sugar, which is now known as Fruit of Beelzebub or high-fructose corn syrup (we’ll say no more about that).

Invert syrup, being mostly sucrose, is every bit as sweet as table sugar. Which means that if you substitute it for corn syrup in any great quantity, you may end up creating a monster of sweetness.

Still, if you keep that in mind and compensate accordingly, you’ll find that you can indeed substitute invert sugar syrup for corn syrup in most pastry and candy applications.

19 thoughts on “Can invert sugar syrup be used in place of corn syrup?”

  1. Honey make a great sub for invert sugar. If I’m not mistaken, and I may very well be, it actually is a form of invert sugar.

    Cheers

    1. Hey Paul! Indeed honey does contain a proportion of invert sugar. The amount varies, but generally it’s not as much as an invert sugar syrup, as evidenced by the fact that honey frequently crystallizes. Still it makes a decent substitute in a pinch!

      Thanks Paul!

      – Joe

  2. Hey Joe!

    In certain candy applications you can also sub out honey for corn syrup, as long as you remember that honey is sweeter and can sometimes crystallize. It’s much better tasting!

  3. How about substituting glucose syrup for corn syrup? For example, in a poured fondant recipe. It seems much thicker so would I have to adjust the ratio of liquid?

    1. Hi Dria!

      Glucose syrup is in fact corn syrup, just a very low-moisture variety, which is why it is so thick. To make the substitution you’d just use about 15% less glucose syrup and make up the rest with a little water.

      Great comment!

      – Joe

  4. Oh, thank you…um…to compensate accordingly, should we use as much invert sugar as corn syrup and reduce the sugar in the recipe? By how much? Or should we use less invert sugar than corn syrup and keep the sugar in the recipe the same? If we use less invert sugar than corn syrup do we increase the chance of crystalization? Is my math correct — invert sugar is approximately 75% sweeter than corn syrup? Yikes! This is sounding more complicated than your cannelles.

  5. Huh. What exactly was the impulse behind finding a substitute for molasses? It seems like molasses pretty much does the job it needs to do, so I’m curious what would cause us to search for a substitute. Increase in the use of sugar beets vs. cane? Expense of production? Some kind of weird hatred for molasses?

    1. Hi V.,

      You answered your own question! The rise of corn syrup was directly tied to the rise of sugar beets, which began replacing cane sugar in the States in 1890 (we were very late adopters of beets). Beets make lousy molasses, but grow in more climates that cane, and so are more versatile, less expensive sources of sugar…at least for people living up north. Corn syrup happened to come along about that time (the early 1880’s), and made a handy replacement for molasses. It was less expensive, easy to produce, had a cleaner taste and could generally be used for more things. It was also free of the taint of slavery, which all cane products carried from the earliest days of the colonies up until well after the Civil War. So from the vantage point of industrial-era consumers, it was pretty much a win across the board.

      Great question!

      – Joe

  6. Recipe for modeling chocolate required corn syrup. I want to know can I use invert syrup and if so how much should I change the ratio?

    1. Hello Fluxme!

      You certain can make the substitution 1-1, though your modeling chocolate will be sweeter than it would have been with corn syrup. If that’s not a problem, proceed!

      Cheers,

      – Joe

  7. I was on a quest to make moist madeleines and foudn a recipe from Pierre Herme that used caramel and invert sugar. I will try it with corn syrup tomorrow.

  8. Thank you Joe!
    I’ve been struggling, trying to make a batch of Christmas recipes and in my country there is no corn syrup at all!
    Fortunately I do make my own inverted sugar! I’ll give it a try!

  9. Hi Joe! If making marshmallows, what is the ratio when substituting corn syrup for inverted sugar syrup?

    1. Hi Vee! Sorry for the late reply. Just substitute it 1-1 and you should have no problems. It won’t taste as sweet, but functionally it should be fine.

      – Joe

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