Yes, your preference for black licorice has a genetic component. The same gene that determines whether broccoli tastes bitter or bland to you also influences how you perceive the strong, polarizing flavor of black licorice. But genetics isn’t the whole story: your cultural exposure, childhood eating habits, and individual taste receptor makeup all play a role in whether you love it or hate it.
The Gene Behind Bitter Taste
The gene most relevant to black licorice preference is TAS2R38, which codes for a receptor on your tongue that detects certain bitter compounds. This gene comes in two common versions. One version, called PAV, makes you significantly more sensitive to bitter flavors. The other, called AVI, leaves you relatively unbothered by them. You inherit one copy from each parent, so you can end up with two sensitive copies, two insensitive copies, or one of each.
People who carry at least one PAV copy are more reactive to bitterness in general. They’re the ones who tend to find black coffee harsh, grapefruit juice unpleasant, and cruciferous vegetables like kale or Brussels sprouts hard to enjoy. Black licorice, with its layered bitter and sweet profile, falls into this category of divisive foods. If you have two AVI copies, you’re less likely to pick up on the bitter edge of licorice, which may make the overall flavor more appealing rather than off-putting.
What Makes Black Licorice Taste So Strong
Black licorice gets its distinctive flavor from two main sources. The first is glycyrrhizin, a compound that makes up 10 to 25 percent of licorice root extract. Glycyrrhizin is unusual because it’s intensely sweet (about 50 times sweeter than table sugar) but also carries a lingering, slightly bitter aftertaste. The second is anethole, the same compound that gives anise and fennel their characteristic flavor. Together, these create that unmistakable taste people either crave or can’t stand.
The reason black licorice is so polarizing comes down to how your particular set of taste receptors responds to this combination. Someone with high bitter sensitivity might perceive the glycyrrhizin’s aftertaste as dominant and unpleasant, overwhelming the sweetness. Someone with low bitter sensitivity might barely notice it, tasting mostly a rich, herbal sweetness instead. It’s not that one group is “right” about the flavor. You’re literally tasting different things from the same piece of candy.
Supertasters and the Licorice Divide
Roughly 25 percent of people are considered “supertasters,” meaning they have both the genetic sensitivity and a higher density of taste receptors on their tongues. These individuals experience all flavors more intensely, but bitterness hits them especially hard. Another 25 percent are “non-tasters” who perceive bitterness only weakly, and the remaining 50 percent fall somewhere in between.
Interestingly, while researchers have studied the connection between TAS2R38 and preferences for foods like broccoli and coffee in detail, the specific link to licorice preference hasn’t been formally tested in large studies. The University of Washington’s Genome Sciences program has noted this gap, pointing out that “the preference for licorice has never been studied” in the same rigorous way. Still, the underlying mechanism is well understood: if your genetics make you more sensitive to bitter compounds, you’re less likely to enjoy foods and candies where bitterness is a prominent note.
Why Humans Evolved to Taste Bitterness Differently
Bitter taste receptors exist for a reason. In nature, toxic substances often taste bitter, and the ability to detect them likely protected early humans from eating poisonous plants. Over time, different human populations developed different levels of bitter sensitivity depending on the plants available in their environments. This is why the TAS2R38 gene shows so much variation across the world: there was no single “correct” level of bitter sensitivity that worked for everyone.
This evolutionary history helps explain why black licorice preferences often cluster in families and ethnic groups. Scandinavian countries, for example, have a strong cultural tradition of eating salty black licorice (salmiak), which suggests both genetic predisposition and repeated exposure from childhood work together. If your parents liked it and fed it to you early, you were more likely to develop a taste for it, especially if your genetics didn’t make the bitterness overwhelming.
The Health Side of Licorice You Should Know
Whether you like black licorice or not, it’s worth knowing that glycyrrhizin does more than create flavor. Once you eat it, your body converts glycyrrhizin into a compound that blocks an enzyme in your kidneys responsible for deactivating cortisol, a stress hormone. When that enzyme is blocked, cortisol builds up and starts activating receptors that increase sodium retention and potassium loss. The result can be high blood pressure, low potassium levels, and in serious cases, irregular heart rhythms.
The FDA warns that if you’re 40 or older, eating just 2 ounces of black licorice a day for two weeks or more could cause problems serious enough to require hospitalization. That’s not a large amount, roughly a handful of licorice twists. A typical serving of about 1.5 ounces already contains 17 grams of sugar and 140 calories, so the health concerns extend beyond glycyrrhizin alone. Occasional indulgence is fine for most people, but daily snacking on real black licorice (not artificially flavored versions, which usually contain no actual licorice root) carries genuine risks.
Genetics Sets the Stage, Experience Fills It
Your genes give you a starting point by determining how sensitive your tongue is to the bitter compounds in black licorice. But taste preferences are also shaped by what you ate growing up, how often you were exposed to similar flavors, and even your current diet. People who regularly eat bitter or complex foods tend to build tolerance over time, which is why some adults who hated black licorice as children eventually come around to it.
So if you’ve always wondered why your friend devours black licorice while you can barely stand the smell, the answer is partly written in your DNA. The TAS2R38 gene is the biggest single genetic factor, but it works alongside dozens of other taste receptor genes, your personal history with food, and cultural norms to produce your final verdict on one of candy’s most divisive flavors.