The chewiness of a gummy candy comes from a network of protein chains that trap water and sugar inside a flexible, springy gel. In most gummies, that protein is gelatin, which forms microscopic structures called triple helices as it cools. These helices act like tiny joints in a three-dimensional mesh, giving the candy its signature bounce. The specific balance of gelatin strength, sugar concentration, moisture, and acidity determines whether you get a soft, jiggly bear or a tough, rubbery vitamin.
How Gelatin Creates That Bounce
Gelatin is made from collagen, the structural protein in animal skin and bones. When collagen is processed into gelatin and dissolved in hot water, its long protein chains float freely in solution. As the mixture cools, those chains begin wrapping around each other in groups of three, re-forming the triple helix structure they had in collagen. These helices act as junction points, linking chains together into a mesh that holds everything in place.
This re-association happens at specific temperatures. Pork-derived gelatin, the most common type in candy, begins gelling around 26 to 28°C (roughly 79 to 82°F). The result is a matrix that’s remarkably elastic: you can bend a gelatin gummy and it springs back into shape because the protein strands stretch without breaking. That resilience is what separates a gummy bear from, say, a hard candy or a marshmallow.
The triple helices also explain why gummies melt in your mouth. Commercial gelatin gummies have a melting point around 45°C (113°F), which is close enough to body temperature that the helices start unraveling on your tongue. This gives gelatin gummies that slippery, almost liquid feeling as you chew. As one confectionery scientist put it, “gelatin gels just totally melt in your mouth.”
Sugar and Water Do More Than Add Sweetness
A gummy isn’t just gelatin and water. Sugar and corn syrup make up the bulk of the candy, and they play a structural role beyond flavor. These sweeteners crowd around the gelatin network, reducing the amount of free water available and making the gel firmer and more stable. A finished gummy typically reaches about 83% dry solids, meaning only around 17% of its weight is water. That low moisture content is critical: too much water and the gummy is floppy and spoils quickly, too little and it becomes hard and unpleasant to chew.
Corn syrup (or glucose syrup) also controls crystallization. Without it, the sucrose in the candy would form sugar crystals over time, turning your gummy grainy. The mix of different sugar molecules keeps everything in a smooth, amorphous state, preserving that clean, glossy texture.
Gelatin Strength Varies by Design
Not all gelatin behaves the same way. Manufacturers measure gelatin’s gelling power in “Bloom,” a scale that runs from 50 to 300. Higher Bloom means a firmer, more elastic gel. Gummy bears specifically use gelatin in the 200 to 250 Bloom range at concentrations of 7 to 9% of the recipe. This range hits the sweet spot: firm enough to hold a shape, elastic enough to chew comfortably, and strong enough to melt smoothly rather than crumble.
Lower-Bloom gelatin would produce a softer, stickier candy. Higher concentrations would make something unpleasantly rubbery. The precise ratio is why homemade gummies rarely match the texture of commercial ones, since kitchen recipes often don’t specify Bloom strength.
Why Acid Can Make or Break a Gummy
Most gummies have a pH between 3 and 5, thanks to citric acid or other fruit acids that provide tartness. But acid doesn’t just affect flavor. It actively breaks down gelatin’s protein chains through a process called hydrolysis, weakening the gel network. The lower the pH, the fewer triple helices form, and the softer the candy becomes.
This creates a balancing act for manufacturers. Sour gummies need enough acid for flavor but not so much that the gel falls apart. One reason sour gummies are often coated with citric acid crystals rather than having all the acid mixed in is to protect the gelatin network during production. The high sugar content offers some protection against acid degradation, but heavily acidic formulations still lose noticeable gelling power.
How Gummies Set in the Factory
Commercial gummies are made using a “mogul” process. The hot liquid mixture, typically around 80°C or higher, is deposited into molds made of cornstarch powder. These starch molds serve two purposes: they shape the candy and draw moisture out of it. The trays sit in a drying room at around 21°C and 35% relative humidity, where the gelatin cools and sets while excess water evaporates into the starch.
Research on this curing process shows that gummy texture stabilizes after about 16 hours, even though many manufacturers leave trays in the drying room for up to 24 hours. After demolding, the gummies are tumbled to remove starch, then coated with oil or wax to prevent sticking. The entire process from liquid to finished candy takes roughly a full day.
Pectin and Starch Gummies Feel Different
Plant-based gummies replace gelatin with other gelling agents, and the texture difference is noticeable. Pectin, derived from fruit peels, creates gummies that are less squishy and elastic than gelatin versions. They have a firmer bite with a clean snap when you chew through them, rather than stretching and bouncing back. Pectin gummies don’t melt on the tongue the same way because pectin gels aren’t disrupted by body heat the way gelatin’s triple helices are.
Starch-based gummies sit somewhere between the two. As starch concentration increases, gummies become more adhesive and chewy. Acid-thinned starch, where the starch molecules are partially broken down before use, is common in commercial production because it creates a smoother gel. But push the starch content too high and the candy becomes excessively hard. Research comparing different starch levels found that doubling the concentration nearly doubled the measured hardness and significantly lowered taste-test scores.
Vegan formulations often blend multiple gelling agents to approximate gelatin’s texture. One approach combines pectin with agar (a seaweed extract) to produce gummies that are less sticky and moderately elastic. Optimal results in recent formulations used 10% pectin with 1.5% agar. Even so, replicating gelatin’s unique combination of stretch, bounce, and melt-in-your-mouth finish remains one of the harder challenges in candy science. Each plant-based alternative brings part of the equation but not the whole package.
What Determines Softness Over Time
Gummies change texture during storage, and moisture is the main driver. As water slowly migrates out of the gel matrix, gummies get progressively harder and chewier. This is why an old bag of gummy bears feels noticeably tougher than a fresh one. Storage temperature matters too: heat can partially melt the gelatin network, causing gummies to deform or stick together, while cold temperatures firm them up.
The sugar system also evolves. Over weeks and months, glucose and sucrose molecules can slowly crystallize, creating a grainy texture. Manufacturers control this through precise sugar ratios and sometimes by adding sorbitol or other sugar alcohols, which resist crystallization and help the candy retain moisture longer. That’s why sugar-free gummies, which rely heavily on sugar alcohols, often have a softer, slightly different chew than their sugar-containing counterparts.