Gum, whether it's classic chewing gum or the stretchy delight of bubble gum, is a confectionary marvel. At its core, gum is a soft, malleable candy that delivers a burst of flavor and long-lasting chewability. People of all ages have enjoyed gum, making it one of the most iconic and enduring sweet treats in the world. 

Chewing gum has ancient roots, with early forms used by Greeks, Mayans, and Indigenous Americans. Commercial gum emerged during the 19th century, led by figures like Thomas Adams and companies like the Wrigley Company. Bubble gum was invented by Walter Diemer in 1928.  

Gums were initially made from natural tree resins (chicle, mastiche and other tree saps) and waxes were chewed, evolving later to synthetic materials.

There are several types of gum available, each offering unique characteristics, including chewing gum, characterized for its long-lasting taste, and bubble gum, designed for creating bubbles when chewed. Bubble gum has a stretchy, elastic texture.

Gum shapes vary as well, where the gum industry continues to innovate by delivering different shapes and consumption experiences. Some of the most common are stick and tab gums, pellet gums that will have a panned cover, chunk gums, gum balls, center filled gums, gum and candy combinations (ex. gum filled lollypops) and tape gums.

The main ingredient of gum is called gum base, responsible for providing its chewing characteristics. Gum base is a mixture of plasticized rubber polymers (natural or, most commonly, synthetic), which wont dissolve in the mouth. Each company has its own gum base mix recipe with different additives that will provide unique sensorial characteristics to their products. The primary components of modern gum are the food-grade synthetic rubber polymers, particularly butyl rubber (IIR), styrene-butadiene rubber (SBR) and polyisobutylene (PIB).

Gum production is a fascinating blend of art and science, with specialized machinery ensuring precision and consistency.

Mixing: The gum base, sweeteners, softeners and colorings are mixed in large vats. Batch mixing is more common than continuous mixing. Temperature, ingredients, the addition order and mixing duration are critical to achieve the desired texture and consistency. The most common equipment used are sigma mixers with high-torque, which will mix the high viscosity mass and scrape the surface of the mixer. Sometimes, the gum base is preheated before mixing in hot rooms or heated in the jacketed sigma mixer to soften it up before introducing the other ingredients. For continuous mixing processes, a blade and pin mixer or a twin-screw extruder is used while all the ingredients are added through different streams. Newer technologies allow one to also make the gum base mix in the same process.

Curing: If gum is not going to be pre-extruded, a curing time is needed to avoid shape distortions after extrusion.

Pre-extrusion:  This process is done to minimize shape problems due to the elastic properties of the gum.

Forming/extrusion: The mixed gum is then extruded through a series of rotating screws or rollers, depending on the final shape of the gum: sheets, hollow tube, filled pellets, chunks, etc. If the gum will be filled, powders and jellies for the filling can be co-extruded.

Cutting: For stick or tape gums, the mass passes through different shaping and cutting devices to achieve final thickness and size.

Conditioning/curing: Gums might be put into a curing room for several hours to allow it to cool and crystallization is completed. This will help the gum to be firm enough to be packed.

Coating/panning: A thin layer of powdered sugar or other coatings may be added to prevent sticking and enhance the gum's shelf life. Some gum balls or pellets will go to panning to be panned coated.

Wrapping: Once coated and flavored, the gum is wrapped in individual packages, often foil or paper, before being packaged in larger quantities for distribution.

Formulating a gum requires special attention to the ingredients’ interactions to choose the best combinations to assure a long-lasting flavor experience and nice texture.

Gum base will give all the textural characteristics. Adjusting the type and proportion of the ingredients in the gum base can help one achieve the desired texture. A higher percentage of elastomers will result in a softer gum, but too much will make it rubbery. If it is high in softeners, this will make it waxy, and if it is low in texturizers, this will make it slimy.

For sugar-free gums, it’s important to mention that the election of sweetener and high intensity sweetener will define the sweetness release. Therefore, a combination of more than one sweetener or the use of encapsulation technologies will help achieve a sweetness release like a sucrose one.

Flavor selection should be tailor-made as it will be linked to the three phases of the gum base to assure a long-lasting flavor as well as appealing to aroma and trigeminal receptors. Flavors might plasticize or soften the gum base, too. Taste test extensively to find the perfect ratio of sweeteners and flavorings.

When formulating a gum with a flavor that needs the addition of acid, an acid-resistant gum base should be used.