Does brewing method change caffeine levels?

The common misconception that brewing method fundamentally changes the chemical efficiency of caffeine extraction is largely overstated. Caffeine is highly soluble in water; research indicates that the vast majority of available caffeine is extracted within the first few minutes of contact with hot water. Therefore, the 'strength' of caffeine in your cup is less about the physics of the brewing device and more about the concentration of the beverage itself.

From a producer’s perspective, the coffee bean’s origin and species—specifically the higher caffeine content found in Robusta compared to Arabica—are the primary determinants of potential caffeine yield. However, the brewer dictates the final delivery. Espresso, for instance, creates a high concentration of caffeine per milliliter because it uses a very fine grind and a tight coffee-to-water ratio, forcing a high density of solubles into a small volume of liquid. In contrast, a French press or a large-batch drip brew may contain more total caffeine per serving simply because the user is consuming a larger volume of water that has been exposed to a greater mass of coffee grounds.

Farmers and producers focus on the quality of the cherry and the drying process, but the roaster and the home brewer ultimately control the 'dose.' If you are looking for a specific caffeine intake, the most reliable variable to adjust is the weight of the dry coffee used, rather than the brewing method itself. Whether you use a V60 or a Moka pot, the total caffeine extracted is ultimately limited by the amount of coffee you put in the basket.