How Indonesia's Charcoal-Infused Coffee Takes Your Brew To The Next Level

Kopi joss, also known as charcoal coffee, is a unique drink from Yogyakarta, Indonesia, that has piqued coffee lovers' interest since its introduction in the 1960s. It's made by dropping a piece of burning charcoal into a cup of sweet Javanese coffee, a method that not only adds a touch of theatricality but also results in a smoother brew. Not to be confused with kopi luwak, the world's most expensive coffee, the origin of kopi joss is credited to a local coffee stall owner, known as Mr. Man, who reportedly developed the method to quickly reheat his coffee while possibly trying to find a way to ease a stomach ache.

Kopi joss is prepared using a Java coffee base, which combines ground coffee and sugar in a glass. Then, water that has been heated to the ideal temperature is poured over the mixture, and a red-hot piece of charcoal is added. The charcoal creates a sizzling display while making a "joss" sound — which certainly helps explain the name. This unique twist is also believed to neutralize the coffee's acidity and caffeine content, resulting in a milder brew that is gentler on the stomach and easier to digest.

Coffee has been widely recognized for its antioxidant properties, which help combat free radicals. It also has the potential to increase cognitive functions. Charcoal, particularly in its activated form, has been used for centuries as a natural remedy, often to alleviate digestive issues or remove toxins from the body. Combine the two together, and you get a powerhouse brew: kopi joss.

Similarly to how the long steeping process of cold brew coffee helps reduce its acidity, kopi joss achieves this effect by adding charcoal. Cold brew is made by steeping coffee grounds in cold water for 12 to 24 hours, which slows the extraction of compounds like chlorogenic acids. These types of acidic compounds can contribute to coffee's sharp or bitter taste and may irritate sensitive stomachs. Similarly, the heat from the searing charcoal in kopi joss actively neutralizes the acidity in the hot coffee.

Kopi joss shows how traditional practices can adapt in creative ways. By adding a simple ingredient like charcoal, this Indonesian coffee changes its flavor and creates a unique drinking experience. The charcoal not only reduces the coffee's acidity but also demonstrates how familiar ingredients can be used differently. This combination of tradition and creativity makes kopi joss a standout in the world of coffee.