If you've ever wondered whether the coffee you drink in the morning has more or less caffeine depending on its roast level, you're not alone. Although the flavor and aroma of coffee vary significantly between a light, medium, or dark roast, the amount of caffeine doesn't always follow such a clear pattern. What factors really influence it? Does the roast level significantly affect caffeine, or are there other factors at play?

In this article, we'll analyze how the roasting process alters coffee beans and demystify the relationship between roast level and caffeine content. You'll also discover other key factors that determine how much of this stimulant reaches your cup, helping you choose the type of coffee that best suits your needs and preferences.

What is coffee roasting?

Coffee roasting is the process that transforms green or raw coffee beans into the aromatic brown beans we know.

This process alters the chemical structure of the grain, highlighting its unique flavor and aroma.

You're probably here to find out which roast has the most caffeine . We'll get to that, but there's some important information you should know first.

Coffee roasting processes:

1. Load: The roaster adds the green coffee beans to the roasting machine.
2. Drying: The machine heats the beans for 6–8 minutes to remove moisture (at temperatures of approximately 320°F/160°C).
3. First Crack: The beans make a cracking sound as moisture escapes, signaling the start of the roast (385°F/196°C).
4. Browning : Sugars caramelize, causing color changes and aroma development (up to 473°F/240°C).
5. Second crack: A louder crack indicates internal expansion of the kernels (up to 450°F/232°C).
6. Development: The roast reaches the desired color and flavor profile (determined by roasting time and temperature).
7. Cooling: The beans are cooled rapidly to stop the roasting process and lock in the flavors.

Think of coffee roasting like baking a cake. Raw ingredients don't have the same rich flavor as a baked cake. Roasting works in a similar way.

There's a lot more to this process than I've explained, but what I've mentioned should give you a general idea of ​​how it works.

Does coffee roasting affect caffeine content?

Although the roast level changes the flavor of coffee , it has a minimal impact on the caffeine content within an individual bean.

During roasting, the beans lose water and expand, which affects their density. This means that if you measure coffee by volume (tablespoons), a light roast will have more caffeine because the beans are denser.

However, if you measure coffee by weight (grams), the caffeine difference between light and dark roasts becomes insignificant.

Factors that really affect the caffeine in your drink:

• Bean variety: Robusta beans have more caffeine than Arabica beans.
• Altitude: Beans grown at high altitudes (such as in the Andes) tend to have lower caffeine levels [2].
• Preparation method: Methods with longer extraction times (e.g., cold brew concentrate) produce a higher caffeine content than faster methods (such as espresso).
• Grind Size: A finer grind exposes more surface area, increasing caffeine extraction and dose in your cup.
• Water temperature: Warmer water extracts more caffeine than cooler water.
• Serving size: A larger serving of coffee (e.g., 12 ounces versus 6 ounces) will contain more caffeine.
• Coffee Quality: Rancid beans may lose some caffeine over time.
• Barista skill: Grind size, brewing method, and coffee-to-water ratio all impact caffeine content.

This answer probably wasn't what you expected, but it's vital information to better understand the topic.

Dark vs. Medium vs. Light Roast

This is what you came for:

*Assuming an average grain weight of 0.1 grams.

The table suggests that lightly roasted Robusta beans, when measured by the tablespoon, have more caffeine than their medium and dark roasted counterparts.

The type of bean also affects caffeine in various roasts.

A breakdown of caffeine content by bean type:

• Robusta: Approximately 5–10 mg per bean.

Espresso is a preparation method, not a single bean type. A roaster can use any bean variety (usually Arabica or Robusta) and roast it to the espresso level.

Which roast should I choose?

• If you're sensitive to caffeine, try light roasts or Arabica beans for less caffeine.
• If you have moderate sensitivity, enjoy any roast, but focus on shorter brew times.
• If you're looking for a caffeine boost, dark roasts or Robusta beans are your best bet.

The coffee preparation method and serving size influence caffeine intake more than the roast level or type of beverage you choose.