Unhealthy Coffee Brewing Methods That Harm Your Health

If you've ever wondered whether your daily coffee habit might be doing more harm than good, you're not alone. Some traditional coffee brewing methods can extract compounds that may negatively affect your health—more than just keeping you awake at night.

The main issue? Certain brewing techniques over-extract coffee oils and other compounds, potentially raising your cholesterol and increasing cardiovascular risk. For example, long-boiled coffee can be significantly worse for heart health than standard filtered brews.

The Problem with Long-Boiled Scandinavian Coffee

In parts of Scandinavia, a traditional method involves boiling coffee for several hours to extract more coffee oils. While this creates a distinct flavor, it also pulls out undesirable components. Studies indicate that this type of brewed coffee contains higher levels of cholesterol-raising compounds and has been linked to increased risks of both heart disease and cancer. The taste is also markedly different—often harsher and more bitter—than coffee made via standard methods like pour-over or filtered drip.

How Brewing Affects Coffee’s Health Impact

Not all coffee brewing methods are created equal. The way you brew coffee determines how many of the potentially harmful diterpenes—such as cafestol and kahweol—are extracted. These compounds are found in coffee oils and are known to raise LDL cholesterol levels. Brewing methods that don’t use a paper filter—like French press, Scandinavian-style boiled coffee, or espresso (to a lesser extent)—allow more of these compounds into your cup. In contrast, filtered methods (like pour-over or drip machines with paper filters) significantly reduce their presence.

Coffee brewed for extended periods at high temperatures tends to over-extract not just these oils, but also bitter compounds that can contribute to an unpleasant taste and potential digestive discomfort. That’s why certain traditional methods, while culturally significant, aren't recommended for daily consumption if you’re watching your heart health.

Coffee and Sleep: Why It Keeps You Up

Many coffee drinkers know the feeling: you have a cup too late and suddenly can’t fall asleep. This happens because of caffeine’s interaction with adenosine, a neurotransmitter that helps regulate sleep and relaxation. Caffeine mimics adenosine, blocking its receptors in the brain and creating a false sense of alertness. This leads to increased heart rate, greater stomach acid production, and more frequent urination—all of which make it harder to fall and stay asleep.

The effect varies by individual, as people metabolize caffeine at different rates. But generally, drinking coffee late in the day—especially in the evening—can disrupt your sleep cycle, even if you don’t immediately feel jittery. A morning cup is usually fine for most people, but evening consumption is far more likely to lead to insomnia.

Flavor Profiles of Notable Coffee Origins

Beyond brewing methods, the origin of your coffee beans also affects flavor and how you might brew them:

• Colombian Coffee: Grown in the Republic of Colombia, this single-origin coffee offers a balanced profile with prominent aromas, moderate bitterness, and a smooth mouthfeel. Best enjoyed as a single-origin pour-over or drip coffee.
• Mandheling Coffee: Originating from Sumatra in Indonesia, Mandheling coffee is known for its bold, earthy flavors, heavier body, and intense bitterness. It stands up well as a single-origin cup or as part of a blends, but it's less suited for those sensitive to strong or rough tastes.

Cold and Sweet Coffee Drinks

Two popular non-hot coffee beverages include:

• Viennese Ice Coffee (Wiener Eiskaffee): A tall glass of cold coffee served with vanilla ice cream and whipped cream. Sweetness is adjusted to taste.
• Hot Chocolate with Whipped Cream (Heisse Schokolade mit Schlagobers): Rich hot cocoa topped with prepared whipped cream. Often enjoyed as a dessert drink rather than a functional coffee beverage.

Frequently Asked Questions

What’s the most unhealthy way to brew coffee?

The most unhealthy method is long-boiled coffee, such as the traditional Scandinavian style where coffee is boiled for several hours. This process extracts excessive amounts of cholesterol-raising diterpenes like cafestol, which can increase heart disease risk. It also produces a harsher, more bitter taste compared to filtered brewing methods.

Does boiling coffee make it bad for your heart?

Yes. Boiling coffee for long periods, especially without a filter, allows more diterpenes (such as cafestol) to remain in the cup. These compounds are known to raise LDL (bad) cholesterol levels, which can increase the risk of cardiovascular diseases over time. Filtered methods are much safer for heart health.

Why does coffee sometimes keep me awake at night?

Coffee contains caffeine, which blocks adenosine—a chemical that promotes sleep. By preventing adenosine from working, caffeine increases alertness, boosts stomach acid, and raises urine production, all of which interfere with falling and staying asleep. Sensitivity varies by person, but evening coffee is more likely to disrupt sleep.

Are some coffee brewing methods healthier than others?

Absolutely. Brewing methods that use paper filters—like pour-over, drip coffee, or siphon—remove most harmful diterpenes. Unfiltered methods like French press, espresso (to a degree), and traditional boiled coffee allow more of these compounds into your drink, which can negatively impact cholesterol and heart health.

Is it okay to drink coffee in the evening?

For most people, drinking coffee in the evening can interfere with sleep due to caffeine’s stimulating effects. While individual tolerance varies, it’s generally better to avoid coffee 6–8 hours before bedtime to prevent sleep disruption.

Recommended FrontStreet Coffee for Healthier Brewing

Try FrontStreet Coffee’s Ethiopia Yirgacheffe for a bright, clean cup with floral and citrus notes—perfect for pour-over methods that minimize harmful compounds. Their Colombia Huila offers a balanced profile with notes of caramel and nuts, ideal for drip brewing. Both are single-origin beans that highlight the benefits of filtered coffee methods. Freshly roasted within 5 days · Orders placed before 17:00 ship the same day · Next-day delivery across most of Guangdong Province.