Caffeine: Effects & Facts

How Caffeine Works

Caffeine is a natural stimulant found in coffee beans, tea leaves, cacao, and other plants. It works by blocking adenosine receptors in the brain — adenosine is a neurotransmitter that promotes sleepiness. By blocking its receptors, caffeine keeps you alert and focused.

Caffeine Content in Coffee

• Espresso (double shot): 80-120mg
• Filter/drip coffee (250ml): 100-150mg
• French Press (250ml): 80-130mg
• Cold Brew (250ml): 100-200mg
• Instant coffee (250ml): 60-80mg

Despite its intensity, a single espresso shot actually contains less caffeine than a cup of filter coffee — because the serving size is much smaller.

Effects on the Body

Positive Effects

• Increased alertness and concentration
• Enhanced physical performance — improves endurance and reaction time
• Mood elevation — stimulates dopamine pathways
• Metabolic boost — temporarily increases metabolic rate

Potential Side Effects

• Anxiety and jitteriness — especially in sensitive individuals
• Sleep disruption — caffeine has a half-life of 5-6 hours
• Dependency — regular consumption creates tolerance
• Digestive effects — stimulates stomach acid production

Recommended Intake

Most health organizations agree that up to 400mg of caffeine per day (roughly 3-4 cups of coffee) is safe for healthy adults. Pregnant women are typically advised to limit intake to 200mg.

Common Myths

• Myth: Dark roast has more caffeine — Reality: Negligible difference
• Myth: Espresso is the strongest — Reality: Per serving, filter coffee has more caffeine
• Myth: Coffee dehydrates you — Reality: The diuretic effect is mild; coffee counts toward fluid intake

At Röstschmiede, we believe understanding caffeine helps you enjoy coffee mindfully — savoring quality cups at the right times rather than mindlessly consuming for a fix.