Is decaffeinated coffee safe to drink?

Dear Curious, 

The mighty coffee bean naturally contains caffeine. A jolt of energy is one of the reasons people reach for this brew. However, coffee beans can be processed to remove most of their caffeine. For coffee to qualify as decaffeinated, it must contain no more than 0.1 percent caffeine by weight sample. Today, there are several methods used to decaffeinate coffee. While they’re mostly all considered safe, one solvent in particular—methylene chloride—has come under recent scrutiny for potentially being carcinogenic. Grab a cup and read on to learn more! 

How is coffee decaffeinated? 

There are three main ways to make decaf coffee. The most common way is to use chemical solvents, which are used both directly and indirectly with the beans.  

• In the direct method, coffee beans are steamed and then rinsed directly with a solvent to wash away caffeine molecules.  
• In the indirect method, the solvent never touches the beans. Instead, coffee beans are soaked in water to draw out caffeine and then the caffeine-rich water is then treated with a solvent to flush out caffeine. Finally, the leftover liquid is returned to the beans, allowing oils and other fragrant flavors to be reabsorbed.  

In both methods, the solvents are rinsed or evaporate from the beans and are further vaporized during roasting, leaving only small amounts in the finished product. 

A second method used to create decaf coffee is known as the Swiss Water Process. This process uses only water and carbon filtration. Coffee beans are soaked in hot water to extract caffeine and other compounds. The solution is filtered with a carbon filter which captures large caffeine molecules. The flavorful, decaffeinated extract is then used to wash and filter the next batch of beans. 

Finally, there’s the carbon dioxide method. After beans are soaked in water, they’re exposed to carbon dioxide, which removes caffeine. Using carbon dioxide gas at high temperatures and pressures causes the chemical to act like both a gas and a liquid, allowing it to cover the beans and dissolve the caffeine. 

Is there one decaf process that’s better than the others? 

Some decaffeination processes can alter the taste and aroma of coffee beans. For instance, chemical solvents may cause coffee beans to have a “cooked” flavor. Likewise, the Swiss Water Process can wash away other flavorful compounds, leading to a thin taste. In comparison, the carbon dioxide method produces a more aromatic cup of coffee. This is because carbon dioxide doesn’t affect carbohydrates and proteins in the bean. This preserves more of its taste and flavor.  

That said, these differences in taste and aroma are slight, and can be altered during the roasting process.  

Is decaf coffee safe? 

All three decaffeination processes are considered safe. However, one of the chemical solvents commonly used to make decaf coffee has begun to cause a stir. In 2023, several health advocacy groups submitted a petition to the U.S. Food and Drug Administration (FDA) to ban the use of methylene chloride. Methylene chloride is a chemical used in industrial processes such as paint stripping and metal cleaning. It’s classified as a carcinogen (a substance capable of causing cancer) by the Environmental Protection Agency (EPA) and the World Health Organization (WHO). Ingestion or external exposure to high levels of the substance can have damaging effects on liver and brain function.  

Presently, the FDA allows methylene chloride to be used as a decaffeination solvent. It’s considered safe for use so long as the final coffee product contains less than ten parts per million (0.001 percent) of the chemical residues. While recent consumer testing has shown that methylene chloride is found in small amounts in several brands of coffee, it’s below the FDA’s current limit.  

Should you avoid decaf coffee? 

While the FDA has accepted the petition for review, a decision could take several years. If you want to avoid exposure to methylene chloride, you might consider choosing decaf coffee that’s made with other natural solvents or processes. Consider going for products marked “solvent-free”, “Swiss Water processed”, or “certified organic”. 

Are there any benefits to decaf coffee? 

Before you decide to cease and desist from drinking decaf coffee altogether, it might be helpful to note that decaf coffee does have some health benefits. Coffee beans, even when decaffeinated, are rich in polyphenols. Known for their antioxidant and anti-inflammatory properties, polyphenols may play a part in preventing age-related and chronic diseases like diabetes, high blood pressure, liver disease, and neurological disorders.   

What are some alternatives to decaf coffee?  

If you’re looking for something to replace decaf coffee, the good news is that there are still lots of caffeine-free substitutes available. These include beverages made with chicory root, rooibos, or dandelion root.  

While the jury is still out on whether methylene chloride should be used to make decaf coffee, other processes are considered safe. So, for now, enjoy your cup of joe—caffeine-free!