Black licorice gets its signature flavor from two key compounds: glycyrrhizin, a naturally sweet substance found in the root of the licorice plant, and anethole, an aromatic compound responsible for that distinctive anise-like smell and taste. Together, they create the polarizing flavor people either love or can’t stand.
Glycyrrhizin: The Sweet Base
The licorice plant (Glycyrrhiza glabra) stores a compound called glycyrrhizin in its roots at concentrations of about 5 to 7 percent. This compound is roughly 30 to 50 times sweeter than table sugar, depending on the concentration being compared. Unlike regular sugar, though, glycyrrhizin’s sweetness hits slowly and lingers, giving black licorice that rich, almost medicinal sweetness that sticks around long after you’ve finished eating.
The root has been used for flavoring and medicine for over 4,000 years, and the genus includes about 30 species. Six of those produce meaningful amounts of glycyrrhizin, with Glycyrrhiza glabra being the most widely used in candy production. To extract the flavor, manufacturers typically soak powdered licorice root in a water and ethanol mixture at moderate heat for about an hour, pulling out the glycyrrhizin along with hundreds of other plant compounds that add depth to the final flavor.
Anethole: The Anise Aroma
If glycyrrhizin provides the sweet backbone, anethole provides the smell. This organic compound is the reason black licorice, anise, fennel, and star anise all taste like relatives of each other. Anethole is itself about 13 times sweeter than sugar, so it reinforces the sweetness of glycyrrhizin while contributing the sharp, slightly cooling aromatic note that most people associate with the word “licorice.”
Many commercial black licorice products boost their flavor with anise oil or star anise extract rather than relying on licorice root alone, since anethole is cheaper and easier to source from those plants. Some brands use both, while budget products may skip genuine licorice root extract entirely and lean on anise flavoring to approximate the taste. If you check the ingredient list on your candy, you’ll often see “anise oil” or “natural flavoring” alongside (or instead of) “licorice extract.”
How the Candy Comes Together
The flavor compounds alone don’t explain why black licorice tastes the way it does in candy form. The manufacturing process plays a significant role. Black licorice candy is made by mixing wheat flour, glucose syrup, sugar, oil, starch, and the flavoring agents into a dough, then cooking it under vacuum at temperatures between 125 and 145°C. Wheat flour makes up 25 to 40 percent of a typical licorice candy, far more than in most other soft candies.
During cooking, the starch in that flour gelatinizes and the proteins denature, forming a chewy matrix with the sugars. This is what gives black licorice its uniquely dense, slightly gummy texture. The flour’s starch composition (roughly 25 percent amylose and 75 percent amylopectin) directly controls how firm or chewy the final product feels. That texture isn’t just a vehicle for the flavor. It slows down how quickly the glycyrrhizin and anethole release in your mouth, creating the long, drawn-out taste experience that defines the candy.
Salty Licorice: A Nordic Twist
In Scandinavian and Dutch markets, the most popular licorice isn’t just sweet. It’s aggressively salty, sometimes even harsh. The ingredient responsible is ammonium chloride, also called salmiak salt. This compound activates the same receptor on your tongue that detects sour taste, a protein called OTOP1. Researchers at USC confirmed that ammonium chloride triggers this receptor just as effectively as acid does, which explains the intense, almost stinging sensation salty licorice delivers alongside its sweetness.
Salty licorice has been popular in northern Europe since at least the early 1900s, and the combination of glycyrrhizin’s lingering sweetness with ammonium chloride’s sharp bite creates a flavor profile that’s genuinely unfamiliar to most people outside that region.
Red Licorice Contains No Licorice
If you’re wondering whether red licorice gets its flavor the same way: it doesn’t. Red licorice contains no licorice root extract at all. It’s made using a similar extrusion process, combining sugar with a starchy binder, but the flavoring is fruit-based, either artificial or natural. The name “licorice” in this case refers to the shape and texture of the candy, not the flavor. So the compounds that define real licorice, glycyrrhizin and anethole, are completely absent from the red variety.
Why Too Much Can Be a Problem
Glycyrrhizin isn’t just a flavoring compound. It’s biologically active. When your body processes it, it breaks down into a substance that blocks an enzyme in your kidneys responsible for keeping the hormone cortisol in check. Without that enzyme doing its job, cortisol floods a receptor that normally responds to a different hormone, causing your kidneys to retain sodium and dump potassium. The result, if you eat enough black licorice over a sustained period, is dangerously low potassium levels and elevated blood pressure.
The FDA regulates how much glycyrrhizin can appear in different food categories. Hard candy is allowed the highest concentration at 16 percent glycyrrhizin by weight, while soft candy (which includes most black licorice twists and bites) is capped at 3.1 percent. Beverages sit much lower, at 0.1 to 0.15 percent. These limits exist specifically because the same compound that makes black licorice taste unique can cause real cardiovascular problems at high intake levels, particularly for people over 40 or those already taking blood pressure medication.