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Does Corn Syrup Go Bad?

Does Corn Syrup Go Bad?

Some foods have a pretty short life span. Others can last centuries if stored properly. Take, for instance, honey. As long as you keep it away from moisture, this natural delicacy can last thousands of years before spoiling. If they ever spoil at all.

Don’t believe us? The oldest samples of collected honey that have been found in the ancient Egyptian pyramids are still edible. And they are currently at the graceful age of 3,000 years.

Why are we going back to tombs, pharaohs, and the ancient honey?

Well, we are guessing that you are, at the moment, looking at the jar of corn syrup that’s been sitting on your shelf for ages now and wondering – “Isn’t syrup in its essence very similar to honey? How long can it sit there before going rogue?”

Fortunately, you have come to the right place. The self-life of corn syrup and the ways we can preserve it even longer are the exact topic of our today’s article.

See Also: Does Chocolate Syrup Go Bad?

What’s The Nutritional Content Of Corn Syrup?

But, to answer all these questions and see just how similar corn syrup is to honey, we need to examine what goes in this traditional German recipe. In other words, we are going to take a quick look at this food’s nutritional value.

Corn Syrup Nutritional Value

One tablespoon of corn syrup contains the following elements:

Calories 64
Total fat 0%
Sodium 1%
Total carbohydrate16.78 grams (6%)
Dietary fiber0%

As we can see, the good old corn syrup is, for all intents and purposes, a sweetener you will most likely use to spice up your morning pies. Not too many red flags but not entirely beneficial.

But, we will use this opportunity to point out that high-calorie count, coupled with a strong presence of carbohydrates, points out to the food that, if consumed excessively, can lead to chronic obesity. This comes especially true when it comes to our children who like sweeteners of all sorts and are not as calorie-conscious as the adults are.

Lpc The Added Sugar Our Children Eat Each Day

If we take a look at the image below, we can see that our kids are consuming way too much sugar through candies, beverages, and other groceries that feature artificial sweeteners. There is no need to ramp up the numbers with excessive syrup.

Honey Nutritional Value

But, we are straying off the topic. Let’s do a similar nutritional breakdown for honey and see how the two compare to each other:

Total fat0%
Total carbohydrate17.3 grams (6%)
Dietary fiber0%
Protein0.06 grams

As we can see, the nutritional value of corn syrup and honey is, with the slight exception of iron and sodium, virtually the same. That gives us a lot of hope about the corn syrup’s life expectancy.

The only thing that can ruin these solid foundations is the way the corn syrup is prepared. As we all know, honey is a natural product whose production envelops without any artificial ingredients or processes that could compromise its quality. So, let’s quickly look into this topic as well.

How Is Corn Syrup Produced?

Essentially, corn syrup is the viscous food additive that is produced by heating up or diluting cornstarch with acid. During this process, no preservatives, food supplements, or other ingredients are added to the carbohydrate-high essence that comes from the corn.

Some syrup varieties do feature supplements in the form of molasses and caramel for the purpose of coloring (darkening the syrup) or adding flavor to the mix.

Even so, after all this processing, the corn syrup remains firmly, carbohydrate-based with little to no nutritional elements other than sugar. Why is that important for our discussion?

Well, the bacteria that spoil our food need quite a lot of resources to survive, multiple, and thrive. Doing that in an environment that is scarce in water and almost entirely made of sugar is a tall order. The only way bacteria can get these necessary “survival-packs” is from the outside environment.

So, with that in mind, let’s finally see does corn syrup go bad and how long it can sit on the shelf.

The Final Verdict On The Corn Syrup’s Shelf Life

So, we have seen that the nutritional content of corn syrup gives bacteria very little room to survive. The production process adds nothing that would help annoy invaders to breach these awesome walls.

So, if we would leave the package of corn syrup unopened (unsealed) for an indefinite amount of time, the said syrup would, theoretically, last indefinitely. A similar thing can be said about all other sweetener products like honeymaple syrupmolasses, etc.

Why then, do we have the best-by and use-by date on each bottle of the syrup?

Well, assuming you are not buying the bottle just to keep it on the shelf, you are going to open up the sealed container and use the syrup from time to time. These short exposure to air and airborne bacteria can affect the properties of your favorite sweetener.

Will these short bursts cause the syrup to go bad? Not exactly.

The time frame indicated by the two dates tells us the period in which the corn syrup retains its peak properties. So, for instance, if you have occasionally used the sweetener and the bottle says that your best-by date comes in three years, the syrup will probably be edible even past that date. But, you may lose some of the flavor or the viscosity.

Of course, leaving the bottle wide open in the pantry will cause syrup to degrade to the point where the content will not only become entirely tasteless.

In conclusion, corn syrup has some pretty awesome shelf life margins – you can stretch it from a couple of years to a couple of centuries. The numbers you will ultimately going to get depends entirely on the storage conditions. So, let’s see what we can do about this burning issue.

How To Properly Store Corn Syrup

As you could see from the previous sections, the game of corn syrup storage is based entirely around limiting the exposure to outside elements for as much as possible. By that, we are not talking only about the air and particles that can spoil the liquid.

The other factors that can mess up the syrup’s internal chemistry are sunlight and excessive (or too low temperature).

So, the best thing you can do for your favorite pancake addition is to keep away from the sun safely stored at room temperature. The options for doing this are virtually endless. Still, we recommend the good old kitchen cabinet as your go-to solution.

Also, do your best to seal the bottle cap as hard as you can. You will think about the pains of opening up this pest when the time comes to use the syrup again – nothing that can’t be solved with a simple piece of cloth.

How To Know If The Corn Syrup Has Gone Bad?

This question is much harder to answer since, as we could see by now, the corn syrup can’t exactly go bad. Not unless you treat it very, very poorly. In other words, what constitutes bad will depend entirely on your personal taste. But, let us quickly cover some of the common red flags that should tell you that your good old syrup is probably no longer suitable for use.

1. Best-by Date

Yes, we have previously mentioned that this date doesn’t tell all that much about whether the syrup has gone bad or not. But, you can expect the sweetener to start losing some of its quality past this date. So, if you are an absolute kitchen purist, you take this indication as a sign that the time has come to throw your bottle away.

2. Cloudiness

This often occurs if the bottle hasn’t been capped tightly. If the top surface of the syrup becomes cloudy or you notice the haze anywhere in the bottle, that means moisture has found a way inside the package, and the product has begun to mold. In this case, the syrup is no longer usable.

3. Bubbles

Aside from molding, fermentation is probably the syrup’s biggest enemy, and it happens if some of the foreign food particles have found a way into the bottle. Obviously, if that happens, the syrup should no longer be used. The fermentation usually manifests as the soft and bubbly film on top of the liquid.

4. Smell

Yeah, when it comes to spoiled food, your nose is and will always be your biggest ally. So, open the bottle and sniff its content. If you feel the liquid smells oversweet, bitter, or like alcohol, the syrup has probably gone bad.

5. Taste

Last but not least, you can always open up the bottle and give the syrup a tray. Don’t take too much of it in case something has gone wrong. This is the best method to see if the best-by date is actually valid.


So, there you have it – a comprehensive guide about corn syrup’s shelf life and the methods you can use to see if it’s gone bad. The products like this have an extraordinary life expectancy. But, to get those fabled years of shelf life, you need to make sure the product is stored properly. Take a look at the guidelines we gave you above. If you are careful, you and your favorite corn syrup will have a lot of pleasant years ahead of you.