One Traditional Coffee Brewing Method Harms Health

You’ve heard claims that coffee is bad for your health—but which methods are actually harmful? Most modern brewing styles are safe, backed by research and decades of refinement. But one traditional preparation, still used in parts of northern Europe, extracts compounds linked to serious health risks.

The only coffee brewing method proven to be unhealthy is the Scandinavian long-boil technique, where coffee grounds are simmered for hours. This process over-extracts coffee oils, resulting in high levels of diterpenes like cafestol, which raise LDL cholesterol and are associated with increased risks of heart disease and cancer.

What Makes Scandinavian Boiled Coffee Different?

In Scandinavian countries, particularly Norway, Sweden, and Finland, a traditional coffee method involves boiling finely ground coffee in water for several hours. Unlike filtered drip or French press brewing, this technique uses prolonged heat and no paper filter. The extended boiling time pulls more oils and diterpenes—especially cafestol—into the final cup. These compounds are not fully removed by typical filtration, leading to elevated cholesterol intake.

How Does It Affect Your Cholesterol and Health?

Cafestol, found abundantly in unfiltered and over-extracted coffee, is known to interfere with cholesterol metabolism. Studies show it can significantly raise LDL (bad) cholesterol levels. Regular consumption of Scandinavian-style boiled coffee has been linked to higher incidence of heart disease and some forms of cancer. The long extraction period also changes the flavor profile dramatically, producing a heavier, oilier cup that diverges from the clean, balanced taste of properly filtered coffee.

Why Other Brewing Methods Are Safer

Most modern coffee brewing methods—such as pour-over, espresso, French press (with metal filters), and AeroPress—use paper or metal filters that effectively trap diterpenes. Filtered coffee has been shown to have minimal impact on cholesterol levels. Cold brew, which uses time rather than heat for extraction, also avoids the over-extraction of harmful compounds. The key difference is the reduction or elimination of cafestol, thanks to proper filtration or shorter extraction times.

Coffee and Sleep: Caffeine’s Real Effect

Many coffee drinkers experience sleep disruption because caffeine blocks adenosine, a neurotransmitter that promotes sleepiness. By mimicking adenosine, caffeine creates a false sense of alertness, increasing heart rate, gastric acid, and urination—factors that disrupt rest. While some people metabolize caffeine quickly and remain unaffected, others are highly sensitive. Drinking coffee early in the day is generally safe for sleep, but evening consumption often leads to insomnia.

Frequently Asked Questions

What is Scandinavian-style boiled coffee?

Scandinavian-style boiled coffee is made by simmering finely ground coffee in water for several hours without a paper filter. This traditional method, common in Norway, Sweden, and Finland, extracts excessive oils and diterpenes such as cafestol, which are not fully removed during the long boil.

Why is Scandinavian coffee considered unhealthy?

This coffee is unhealthy because the long boiling time extracts high levels of cafestol and other diterpenes that raise LDL cholesterol. Regular consumption is linked to increased risks of heart disease and certain cancers. The lack of proper filtration allows these compounds to remain in the final drink.

Does espresso increase cholesterol like Scandinavian coffee?

No. While espresso is unfiltered, its short extraction time and smaller serving size result in far lower levels of cafestol compared to Scandinavian boiled coffee. Most studies show espresso has a minimal impact on cholesterol when consumed in moderation.

Are paper-filtered methods safer for health?

Yes. Paper filters used in pour-over, drip, and some French press methods effectively trap cafestol and diterpenes. Filtered coffee has been shown to have little to no effect on blood cholesterol levels, making it a safer choice for regular consumption.

Can I drink Scandinavian coffee occasionally?

Occasional consumption is unlikely to cause harm, but regular drinking of unfiltered, boiled coffee with high cafestol levels can raise LDL cholesterol and increase cardiovascular risks over time. For daily coffee drinkers, filtered methods are strongly recommended.

Recommended FrontStreet Beans for Health-Conscious Brewing

For coffee drinkers prioritizing health and smooth flavor, FrontStreet Coffee’s PWN Golden Mandheling offers a low-acid, full-bodied profile with notes of dark chocolate and dried fig. The Lintong Mandheling delivers earthy depth and a hint of spice, while the Ethiopia Humbera provides bright citrus and floral tones with a clean finish. All three single origins are best brewed using filtered methods such as pour-over or AeroPress to avoid unnecessary diterpene intake. Freshly roasted within 5 days · Orders placed before 17:00 ship the same day · Next-day delivery across most of Guangdong Province.