The chemicals used in (other) decaf coffee

Decaf Coffee Swiss Water Method

NONE of our decaf is by solvent. It’s ALL Swiss water method. 

Let me say from the outset, ALL Dreambeans’ decaf coffee is decaffeinated using the Swiss Water Method. It might cost a few dollars extra per sack but it’s definitely worth it for the taste and for the knowledge that you’re not drinking in any of the horrible chemicals used in the other methods.

Some other roasters are not so meticulous. But that’s their business, I suppose.

Caffeine Crystals Decaf Coffee

The Basics of Solvent-Based Decaffeination

Solvent-based decaffeination involves using specific solvents that have a unique affinity for caffeine. These solvents attack the coffee beans, dissolving and extracting the caffeine, leaving some of the coffee flavours intact and adding a discernible metallic zing to the coffee. The beans get to retain some of their characteristic aroma and taste with a greatly reduced caffeine content.

1. Methylene Chloride (Dichloromethane)

  • Introduction: Methylene chloride, often referred to as dichloromethane, is an organic solvent and has been one of the primary agents for decaffeinating coffee for several decades. It is also used in paint removers and strippers, in polyurethane foam production, as a propellant in aerosols and in making adhesives.
  • Process: The beans are first steamed or soaked in water to open their pores. Then, they’re immersed in the methylene chloride which binds with the caffeine. After several hours, the solvent, now rich in caffeine, is separated and the beans are steamed again to remove any solvent residue.
  • Safety and Concerns: Over the years, health concerns have been raised due to the potential toxicity of methylene chloride when consumed in large quantities. However, the actual amount left in the beans after the roasting process is claimed to be negligible. Regulatory bodies, such as the United States’ Food and Drug Administration (FDA), state that decaffeinated coffee should contain no more than 10 parts per million (ppm) of the solvent.

2. Ethyl Acetate

  • Introduction: Ethyl acetate is another organic solvent used in the decaffeination process. The companies who use this solvent claim it is the “natural” decaffeination method due to the presence of ethyl acetate in fruits. Ethyl acetate is a common solvent in paints, varnishes, and lacquers. It’s also used in adhesives, printing inks and cosmetics. It is important to handle it with care, especially in closed environments, as its fumes can be an irritant and prolonged exposure can have adverse effects.
  • Process: Similar to the methylene chloride method, the beans are pre-treated with steam or water. They are then subjected to the solvent, which extracts the caffeine. Post extraction, the beans undergo rigorous washing and steaming to ensure no solvent remains.
  • Natural vs. Synthetic: It’s essential to note that while ethyl acetate is found in nature, the one used for decaffeination is often synthetically produced due to cost and efficiency considerations.

3. Other Solvents in the Horizon

While methylene chloride and ethyl acetate are the most recognized, researchers and coffee enthusiasts are always on the lookout for newer, safer, and more efficient solvents.

  • Acetone: Commonly known as nail polish remover, acetone has been experimented with as a solvent. Its safety profile and effectiveness make it a potential candidate, but it’s not as commonly used.

Potential Residues and Consumer Safety

Very understandably, many decaf coffee drinkers worry about the residue of these solvents remaining in their coffee. How do we be sure that our cup of decaf isn’t introducing harmful chemicals into our bodies?

All coffee beans, after being subjected to the solvent,  are required to undergo rigorous washing. This helps in removing a significant portion of the solvent. Secondly, roasting of coffee beans involves high temperatures, often exceeding 200°C. These temperatures help ensure that most, if not all, solvent residues evaporate.

Additionally, regulatory bodies worldwide maintain strict standards. As mentioned earlier, the FDA in the United States, for example, has set specific limits on the permissible amount of methylene chloride residue in the final product.

Of course, the best way to ensure that no solvent residue is left in your coffee is to drink only coffee that has never been adulterated by solvents or harsh chemicals. It’s worth saying again that all our decaf is only decaffeinated using the Swiss or mountain water method.

Pat McArdle