The Direct Solvent Method is the oldest decaffeination method in existence. It was invented by a colorful, and complicated, figure named Ludwig Roselius. Roselius was the son of a coffee merchant, and blamed his father’s early death on his heavy caffeine consumption. He set out to find a way to decaffeinate coffee.

You can read much more about Roselius’ life in our article on the history of decaf, but suffice to say he ultimately created what we now call the Direct Solvent Method. He patented the process in 1906, and it became increasingly common by the 1930s.

This process involves steaming unroasted coffee beans to open their pores, and then repeatedly rinsing them with a solvent that specifically targets and dissolves caffeine. Initially, Benzine was used as the solvent. It was mostly removed by washing the coffee beans numerous times, but trace amounts of the chemical remained. 

Unfortunately, Benzine was later discovered to be a carcinogen. Other chemicals have taken its place over the years, but many of these turned out to be hazardous as well. Trichloroethylene became a commonly used solvent, but in 1975 this was named a probable cause of cancer. Methylene Chloride followed in its footsteps as an industry standard, but in 1985 the FDA declared that it was potentially carcinogenic. Today, Methylene Chloride is still a commonly used decaffeination solvent.

These chemicals also carried environmental concerns. Many groups were concerned over how solvents were disposed of. As recently as 2023, chemicals used to decaffeinate coffee have been identified as a danger to the ozone layer. 

Chemically processed decaf also led to an inferior product. Low quality coffee beans were often used to make decaf, because the harsh, chemical decaffeination would strip the beans of their flavor. 

Despite its messy history, the Direct Solvent Method can be applied safely and successfully. In fact, one of our favorite decaffeination methods is the Ethyl-Acetate Process. This method relies on an all-natural solvent that is found in ripe fruit and sugar. For this reason, it is often referred to as the Sugarcane process. This process is known for preserving the brightness and acidity of coffee beans. You can read more about it here.