How does the roasting process affect the caffeine content of coffee?

• A. Roasting reduces caffeine content significantly
• B. Caffeine content remains unchanged regardless of roast level
• C. Dark roasts have more caffeine than light roasts
• D. Lighter roasts retain slightly more caffeine than darker roasts

Answer: (D)

The roasting process has a nuanced impact on caffeine content in coffee, with lighter roasts typically retaining slightly more caffeine than darker roasts. This is primarily due to the fact that caffeine is a stable compound that does not break down significantly during the roasting process. While both roast levels will contain similar absolute amounts of caffeine per coffee bean, the loss of mass during roasting translates to a relative increase in caffeine concentration in lighter roasts when measured by volume.

In darker roasts, the beans experience a longer roasting time and higher temperatures, which leads to greater loss of mass and some compound alterations. Consequently, when comparing a given volume of light roast to dark roast coffee, the lighter roast will often have a slightly higher caffeine content. Understanding this relationship helps clarify why those who consume light roasts might find they experience more pronounced caffeine effects than from their dark counterparts.