Why Doesn’t Gum Dissolve?

In many ways, chewing gum is a perfect example of modern chemistry at work. We see miracles of polymers in our everyday lives, from plastic bottles to innovative packaging designs. Have you ever considered all the wonderful science behind such a monotonous food product like chewing gum? The story of chewing gum is long and interesting, starting with simple forest products all the way through to modern and innovative polymers.

The long history of chewing gum

Man blowing a bubble using chewing gum.Chewing gum in the United States became commercially available in the mid -1800’s. Cultures around the world are no strangers to gum-like products. For millennia, people around the world have been creating gum from wood products such as the sap and bark of trees.

The first chewing gum marketed in the United States was created in 1848 by the Curtis family using sap from spruce trees in Portland, Maine. The first patent for chewing gum was filed by a dentist, Dr. William Simple. His gum was a mixture of rubber, sugar, licorice and charcoal for a cleaning effect. The first product that was packaged that looked and tasted more like the modern chewing gum that we see every day was created by a Kentucky pharmacist named John Colgan in the 1860’s. . A traveling salesman named William Wrigley Jr. was a marketing genius and generated widespread popularity for his version of the chewy treat at the turn of the 20th century.

What is “Gum Base?”

Modern chewing gum begins with a “gum base.” Back in the 1860’s, when the first commercial product was available, gum base was made of “chicle,” a natural latex from trees native to Central America, and the namesake for Chiclets. The Aztecs and Mayans chewed this traditional gum long before it was made into commercial chewing gum.

For many years, chicle was the main ingredient in gum base. However, manufacturers eventually began looking for a cheaper alternative to this natural product. During this time of innovation in the 1960’s, we begin to see the exciting science behind chewing gum.

Only a few manufacturers still produce chewing gum using chicle, Glee Gum being one of the most common. For most other manufactures, “gum base” is created using various synthetic rubber that has proven to be cheaper to produce, easier to manufacture and even more effective as a base for chewing gum products.

According to the FDA, gum base can be manufactured using many different approved substances. Chewing gum manufacturers are not required to disclose the exact list of ingredients of their gum base; in fact, they keep this information very private. Wrigley, for example, simply lists gum base as an effective, safe product that they use in the creation of their gum.

As scientists, of course, that isn’t enough information for us. We want to understand the chemistry and science behind gum base, so we dug deeper.

We learned that after chicle was phased out, synthetic rubber became the main ingredient used in gum base. One of these synthetic rubbers is styrene-butadiene rubber (SBR). SBR is a copolymer of styrene and butadiene that used in many different applications, including car tires! Other synthetic rubbers used in gum bases are polyethylene and polyvinyl acetate.

While gum base makes chewing gum sticky and chewy, all the other substances we see in gum are what makes gum a popular and great-tasting confectionery. Without these additional ingredients, chewing gum would just be flavorless and rubbery — not a successful food product.

Why doesn’t gum dissolve when you chew it?

The rubbers used as gum base are not soluble in water. The formulations used by modern manufacturers are suited to stick around (see what we did there?)  a long time in saliva. Some formulations are not even digestible if swallowed and will reemerge as a solid piece. (uh, yuck!) There are enzymes, such as amylase, that can cause gum to break down. Certain foods like peanuts that are stuck to your teeth can cause the same effect. There is even a medical term called Gum Disintegration Syndrome that is given to people whose saliva is incompatible with chewing gum for one reason or another.

In 1996 the Wrigley Corporation patented a new recipe for biodegradable gum. It would have brought an end to sticky clumps on shoes and the black circles on sidewalks from used gum. However, consumers rejected the product because it didn’t stay chewy long enough.

What else makes gum great?

In addition to gum base, many softeners are employed to give chewing gum its intended density and softness. Once the density of the gum is established, sweeteners are used. Xylitol, sorbitol and sucralose are all popular sweeteners for chewing gum.

Gum base, sweeteners and softeners are the main ingredients that make gum, well…gum! One of the most important parts for customers, though, is the taste. Natural and artificial ingredients are both used to flavor chewing gum to transform it into the delicious substance we know and love. From natural peppermint oils to artificial watermelon flavoring, there is no limit to the creativity and innovation in chewing gum flavors!

Here at Polymer Solutions, we’re always inspired by the ways science allows us to see our everyday lives in new and different ways. Given that chewing gum is a 3.9 billion dollar industry in the United States alone, it’s no surprise that it breeds innovation constantly. Chewing gum has come a long way since its humble beginnings in ancient civilizations. From natural products to synthetic polymers, it’s a great example of science and innovation in modern life.

If this post has inspired you to learn all there is to know about chewing gum, there’s some worthwhile reading available on the subject. Chicle by Jennifer P. Williams digs far deeper into this innovative product than we ever could on the blog. Enjoy!

1 Comment


  1. I actually didn’t quite enjoy the article because I chew approximately a whole pack of gum every day…;) Some knowledge is just not worth sacrificing the comfort;)

    Reply

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