Decaffeinated coffee is a great option for those who enjoy the taste of coffee but do not want to experience its stimulating effects. This type of coffee has become very popular lately, but some people think it is a poor quality coffee or even that it is not “real coffee”.
This may have been true in the past, since low-quality coffees were used in the decaffeination process. But nowadays, everything has changed. I will explain why and how the coffee decaffeination process is carried out.
¿What is decaffeinated coffee?
Decaffeinated coffee is coffee that has been processed to eliminate part of the caffeine that is naturally found in it. Although it is impossible to eliminate all the caffeine, decaffeinated coffee generally contains significantly less caffeine than regular coffee.
For decaffeinated coffee, most countries require that the caffeine content be reduced to less than 0.1% in dry weight; however, decaffeinated coffees with up to 0.3% caffeine can be found in the market.https://www.ncbi.nlm.nih.gov/
The decaffeination process is applied to green coffee beans, which are still raw. This happens in industrial plants that extract caffeine through solvents. Even after this process, its flavor and aroma are maintained.
Main stages of the coffee decaffeination process
The coffee decaffeination process is complex but can be summarized in the following stages:
- The inflation of the coffee bean: The coffee beans are moistened with water vapor to make them swell and soften.
- The extraction of the caffeine: The coffee beans are immersed in water or a solvent to extract the caffeine.
- The separation of the water (or solvent) from the caffeine: In the solvent method (which we will see later), the solution undergoes an evaporation process to separate the solvent from the caffeine. In the water method, the water is passed through an activated carbon filter to eliminate the caffeine.
- Coffee bean drying: Coffee beans are dried to remove moisture.
- Packaging of the coffee beans without caffeine: The decaffeinated coffee beans are packaged.
- Laboratory analysis: Tests are performed on the decaffeinated coffee to ensure that the amount of caffeine is below the limit established by industry standards.
Note: It is important to remember that the specific process may vary according to the decaffeination method used and the manufacturer that performs it.
Solvents used for coffee decaffeination
The solvents used to decaffeinate coffee are mainly 4: water, methyl chloride, ethyl acetate, and dichloromethane. Let us see them in detail:
1. Use of water as a solvent
Eliminating caffeine from the coffee bean with water involves immersing the coffee beans in hot water to extract the caffeine from the beans. This process is based on the theory of osmosis, where the hot water dissolves the caffeine but not the other components of the coffee bean.
Eliminating caffeine from the coffee bean with water is considered a more sustainable and less invasive method than other decaffeination methods since it does not use chemical products or solvents to eliminate the caffeine from the coffee bean.
Although it is important to note that decaffeinated coffee using water, including the Swiss Water process, still contains traces of caffeine, as it is impossible to remove all caffeine from the coffee bean completely.
2. Ethyl acetate
Ethyl acetate is a selective solvent for caffeine. However, it has two major drawbacks: it is highly flammable and leaves a strange fruity odor in the coffee.
- The coffee beans are moistened with water to open the pores and facilitate the elimination of caffeine.
- The coffee beans are immersed in an ethyl acetate solution, which selectively dissolves the caffeine.
- Once the caffeine has dissolved, the ethyl acetate solution is removed, and the coffee beans are washed several times with water to remove any remaining ethyl acetate and caffeine residue.
- Finally, the coffee beans are dried, roasted, and ready for consumption.
3. Supercritical carbon dioxide
The decaffeination of coffee with supercritical carbon dioxide is a caffeine extraction process that uses carbon dioxide in a supercritical state as a solvent.
- In this method, green coffee beans are submerged in an extraction tank at high pressure and temperature, where the carbon dioxide is converted into a supercritical state.
- The supercritical carbon dioxide is then injected through the coffee beans, allowing the caffeine to dissolve in the carbon dioxide without affecting other compounds in the coffee.
This decaffeination method is considered safe and environmentally friendly, as it does not use harmful chemicals and does not produce toxic residues.
In addition, this method is believed to produce a decaffeinated coffee with a flavor and aroma very similar to regular coffee, making it popular among coffee lovers looking for a caffeine-free option without sacrificing flavor.
Decaffeinated coffee using dichloromethane is one of the coffee industry’s oldest and most widespread methods. This organic solvent can act selectively on the caffeine, and due to its high volatility, it evaporates easily at low temperatures, leaving the coffee free of this stimulating substance.
- The process involves submerging the raw coffee beans in water with the solvent and allowing the dichloromethane to act on the caffeine.
- The solvent residues are then removed by steam, and the coffee is left to dry.
It is important to highlight that the quality of the decaffeinated coffee obtained with this method is very high since the original characteristics of the coffee in terms of color, flavor, smell, and texture are maintained.
⚠️ Although this method has some advantages, such as the elimination of waxes present on the surface of the raw coffee bean, some experts question its safety and possible impact on health.
¿Are solvents present in the bean?
In the process of decaffeination with solvents, a small amount of solvents may remain present in the coffee bean, but they must be eliminated before sale to the consumer.
For this reason, the industrial plants in charge of the process must perform analyses to verify that the residual content of solvents and caffeine is below certain levels established by the regulations.
In the European Union, the decaffeination of coffee with solvents is regulated by Directive 2009/32/EC, which establishes maximum limits for the residual content of solvents in decaffeinated coffee.
In the United States, the Food and Drug Administration (FDA) regulates the amount of chemical residues allowed in food, including decaffeinated coffee.
Chemical residues are eliminated by washing and drying processes. In any case, the health authorities establish regulations and limits for chemical residues in food to guarantee food safety.
It is important to bear in mind that decaffeinated coffee is not decaffeinated directly by coffee roasters, but rather there are special industrial plants that take care of this.
As a general rule, decaffeinated coffee should undergo the following analyses:
- Analysis of residual caffeine content, which should be less than 0.1%.
- Analysis of residual solvent should be less than 2 mg/kg in roasted coffee.
- Moisture content analysis, which must be less than 11%.
The analyzed coffee cannot be sold if it does not pass these tests.
¿How is decaffeinated coffee prepared?
Preparing decaffeinated coffee is quite similar to preparing regular coffee. You can prepare fresh decaffeinated coffee beans or ground coffee in any coffee maker.
But it is important to remember that decaffeinated coffee can taste slightly different than regular coffee, so you may need to experiment with different preparation methods and brands to find what you like best.
Be sure to consult the instructions of the decaffeinated coffee producer since the preparation recommendations may vary according to the brand and type of decaffeinated coffee you buy.
Decaffeinating coffee is a complex process involving diverse techniques and methods to achieve a cup of decaffeinated coffee with a satisfactory flavor and aroma.
The processes used can be chemical or natural, and both have their own advantages and disadvantages in terms of taste, aroma, cost, and environmental impact.
It is important to highlight that the quality of decaffeinated coffee depends greatly on the process used and the quality of the original coffee. Therefore, the decaffeination processes must be carried out with care and precision to obtain the best possible results in our coffee.