Last weekend, we were handing out samples of Crickle Creek coffee at a Chinook Blast Fat Bike event at Shaganappi Point Golf Course. Between conversations with riders, someone asked me a question I hear often:
“If coffee is roasted longer, does it have less caffeine?”
It sounds logical. We apply heat to coffee for longer to make a darker roast, so surely some of the caffeine must disappear along the way? The answer is a little less tidy—and much more useful when you’re choosing what to drink.
The short answer: A dark roast is not a reliable way to get less caffeine. Roast level can affect caffeine measurements, but the coffee you use, how much you put in the brewer, and how you brew it all affect the amount that ends up in your cup. A bolder taste does not mean a bigger caffeine kick, either.
What does roasting change?
At our Calgary roastery, Alejandro and the team start with green coffee: dense seeds that look and smell nothing like the beans in your grinder. As they heat, the beans lose moisture, expand and turn from green to yellow and then brown.
Roasting also creates many of the aromas and flavours we love. The Maillard reaction—a set of reactions involving sugars and amino compounds—is part of that transformation. Roast a coffee further and its flavour generally moves toward deeper, more roast-driven notes. That is why a dark coffee might remind you of bittersweet chocolate or toast, while a lighter-roasted coffee may make its fruit character easier to notice.
Those are flavour differences. Caffeine is a separate question.
Does dark roast have less caffeine than light roast?
You may have heard that roasting “burns off” the caffeine. You may also have heard that dark roast always has more caffeine because it loses weight during roasting. Both explanations try to turn a complicated comparison into a rule.
Roasting changes a bean’s mass and density, and research has found that roast level can affect caffeine in brewed coffee. But results depend on the coffees and brewing conditions being compared. You cannot look at two bags—one light, one dark—and know which finished cup will contain less caffeine.
That means the honest answer to the question at the Fat Bike event was: choose your roast for the flavour you enjoy, not as your caffeine-control method.
Does it matter whether I scoop or weigh my coffee?
Yes. Darker-roasted beans generally become less dense, so a scoop may hold a different weight of dark beans than it does light beans. If you brew by the scoop, you may be changing your coffee dose without realizing it.
A scale makes your recipe easier to repeat. If you use 20 grams of coffee today and 20 grams tomorrow, you have controlled one important variable. You still have not guaranteed the same caffeine amount: different coffees and brew methods can produce different results.
I know—that is less satisfying than “dark has less.” Coffee has a habit of making simple questions interesting.
Why does dark coffee sometimes feel stronger?
Often, people mean stronger flavour when they say “stronger coffee.” Dark roasting can give a cup a deeper, more intense roast character. Someone else might use “stronger” to mean a higher coffee-to-water ratio, while another person means more caffeine.
Those are three different things. When a customer asks us for a strong coffee, I’d rather find out which experience they want than hand them a dark roast and assume we understood each other.
What if I actually want less caffeine?
Choose a coffee made with less caffeinated coffee. Our Sunnyside Half Caff combines regular and decaffeinated beans for a cup with less caffeine than its fully caffeinated counterpart. If you want to go further, explore our decaf coffees.
Half-caff does not promise an exact number of milligrams in every cup, and decaf is not completely caffeine-free. If you have a specific limit to follow, a roast label—or even the words half-caff—cannot give you a precise measurement. Our guide to half-caff explains the difference and introduces you to Guillermo, our resident Half-Caff Guy.
As for the idea that caffeine stays in everyone’s system for exactly 12 hours: bodies vary. The commonly cited figure is that it takes roughly four to six hours for the body to clear half a dose, though it can take longer or shorter for an individual. That is one reason the same afternoon coffee may suit one person and keep another awake.
So here’s what I’d tell the next person who stops for a sample: drink the roast you love. If caffeine is what you want to change, look at the caffeine level of the coffee and the size of the cup instead.
Brew boldly, live fully
Adriana