Analyzing the DNA of more than 125,000 people, researchers in Montreal found specific genes that may shape people’s coffee preferences.
BY BHAVI PATEL
BARISTA MAGAZINE ONLINE
Featured photo by Elizabeth Tsung
What to know:
- A study conducted by researchers at Montreal’s McGill University found 46 genetic variants linked to how much people enjoy 11 different bitter foods, including coffee without sugar
- Two specific gene variants near caffeine-metabolizing genes were shown to coincide with people’s real-world coffee-drinking habits
- Even with all this genetic detail, researchers found that the effect of any single gene on your actual diet is small, meaning one’s palate is still mostly shaped by habit and culture
Ever wonder why some people can happily sip a pitch-black, unsweetened pourover while others need a heavy pour of cream and sugar? Coffee people have long suspected that a love for a naked, bitter cup comes naturally to some. Now, science is backing that up.
A major study published in The Journal of Nutrition, led by researchers at Montreal‘s McGill University, looked at the DNA of more than 125,000 people. They wanted to find out why different people react so differently to bitter flavors. While the study looked at a few different foods, coffee turned out to be one of the clearest and most fascinating examples.
Why coffee has its own unique genetic code
When researchers looked at how our bodies respond to bitter items, coffee without sugar stood out with some of the strongest and most consistent genetic signals.
Instead of pointing to genes that control how your tongue tastes bitterness, the study found genetic markers near the liver enzymes that process caffeine, specifically in a region involving the CYP1A1 and CYP1A2 genes.
To make sure this wasn’t just a fluke, the researchers tested these genetic variants against real-world coffee-drinking habits in a separate group of over 9,000 adults. The genetic markers held up, matching directly with how many cups of coffee people drink each day.
How you process caffeine matters, not just how it tastes
This is where coffee separates itself from other bitter foods. For instance, liking grapefruit comes down to genes that control your actual taste buds—the physical hardware on your tongue that senses bitterness.
Coffee works differently. Your preference for black coffee doesn’t seem to be about how intensely you taste the bitterness on your tongue. Instead, it is tied to how your body handles and metabolizes caffeine once it is in your system. Your body’s internal engine plays a big role in why you enjoy that flavor profile.
What this means behind the bar
For anyone roasting, brewing, or serving coffee for a living, this research offers a fun new perspective. When a customer walks in and orders an uncompromised, sharply but pleasantly bitter espresso or filter coffee, it isn’t just an acquired taste they forced themselves to learn, nor is it just a passing trend. Part of it is genuinely wired into them. Their genetics dictate how their body processes caffeine, shaping what feels satisfying to their palate.
At the same time, the science keeps things in perspective. Genetics only gives you a small nudge. Your morning coffee ritual is still largely shaped by habit, culture, and the comfort of repetition. Biology might hand you a starting point, but everything you do with that first bitter sip is still entirely your own.
Bhavi Patel is a food writer focusing on coffee and tea, and a brand-building specialist with a background in dairy technology and an interest in culinary history and sensory perception of food.
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