What Determines Caffeine in Coffee Beans and Is It Beneficial to the Human Body?

What Caffeine Does and How Much Coffee Contains

Mention caffeine and the first thing that comes to mind is its stimulating, energizing effect. Legend has it that a flock of sheep, after eating coffee cherries, danced through the night without sleeping — quite a magical phenomenon.

For many people, the workday begins with coffee precisely for that refreshing boost. Historically, people have consumed coffee cherries and beans for their stimulating effects, and for health-conscious coffee lovers, "which coffee has the least caffeine" has always been a popular topic.

What Determines Caffeine Content in Coffee Beans

So what determines how much caffeine a coffee bean contains? First, the variety:

A Robusta bean contains roughly 3.2% caffeine — far more than the 1.5% typical of Arabica. Other coffee species derived from Arabica carry about 1.2%–1.7% per bean. Among these, the low-caffeine Bourbon variety (Laurina) has only half the caffeine — a delicious coffee that legend says lets you sleep well even after several cups, and which was reportedly the favorite of French writers and intellectuals like Honoré de Balzac.

Does Roast Level Affect Caffeine?

Caffeine content is also related to roast degree.

According to a report from the Association for Science and Information on Coffee (ASIC), the caffeine content as a percentage of bean weight in light, medium, and dark roasted Arabica is 1.37%, 1.31%, and 1.31% respectively — light roast is only 0.06% higher. However, light roasts lose 11–13% of their weight during roasting while dark roasts lose 15–17%. Caffeine is lost to sublimation during dark roasting, but the losses are negligible. When you measure coffee by weight, dark roast may actually yield slightly more caffeine than light roast due to the weight loss and extraction efficiency. Roast level, in other words, is not a key factor in caffeine content.

Caffeine and Extraction Method

The caffeine in your cup depends inextricably on extraction. People care about caffeine in the brewed liquid because not all of the caffeine in the beans makes it into the drink — what matters for your intake is how much actually dissolves into the water.

The same beans brewed different ways yield different caffeine levels. Brew 15g of Arabica as pour-over and one cup (200ml of coffee) contains roughly 100–150mg of caffeine; a single shot of Arabica espresso (30ml) contains about 50–100mg.

In general, caffeine release depends critically on extraction time: the longer water stays in contact with the grounds, the more caffeine is released. For the same beans at the same weight, the ranking is: cold brew > French press > pour-over > espresso.

Caffeine: Health Considerations and Benefits

Caffeine has many pharmacological effects. People who are pregnant or have stomach problems should moderate their coffee intake. But consumed in moderation, coffee can effectively relieve fatigue and restore energy.

FrontStreet Coffee Recommendation

If you want to explore how variety shapes both caffeine and flavor, the Arabica family is where the most interesting stories live. FrontStreet Coffee's Huaguoi comes from Ethiopia's Sidamo region, made from the local heirloom varieties most common there — mixed trees produce beans of varying size, with delicate florals and striking fruit character. Classic natural processing brings creamy strawberry, mango, jackfruit, citrus, and blueberry notes, the very lush berry fragrance that won first place in that year's TOH green bean competition, all at a price that makes it an easy daily drinker.

For a washed expression, FrontStreet Coffee's Yirgacheffe Guodingding comes from the Guodingding cooperative, graded Ethiopia's highest G1. It brews with elegant white florals, citrus, orange, and green tea notes — clean, bright, and gentle on the palate.

And for those who prefer lower acidity with a fuller body, FrontStreet Coffee's PWN Indonesia Golden Mandheling is the classic choice. Dark-roasted and smooth, it layers herbal and dark chocolate aromas with just a trace of earthiness — rich and lingering, perfect for drinkers who love bold flavor without the buzz of extra bitterness or acidity.