Coffee beans contain a natural stimulant known as caffeine. Most coffee drinkers choose coffee because of the jolt of caffeine in it. However, consuming high amounts of caffeine will have adverse side effects such as jitters and lack of sleep. Therefore you’ll find that some people prefer decaffeinated coffee with less caffeine.
Decaffeinated coffee is usually associated with less flavorful coffee since numerous flavor chemicals are removed when removing caffeine. Additionally, decaffeinated coffee beans are difficult to roast properly. Several methods are used to remove caffeine from coffee beans. This article will discuss these methods in detail. Read on!
What is Decaffeination?
Decaffeination is the process of removing caffeine from coffee beans as well as tea leaves. Coffee beans naturally contain caffeine which is responsible for boosting your energy levels, enhancing your alertness levels, and elevating your moods, among others. Some coffee drinkers relish the taste of coffee but cannot tolerate the caffeine in it. Thus the development of decaffeinated coffee.
According to U.S. guidelines, a coffee is labeled as decaffeinated only if 97.5% of the caffeine is removed. Therefore, decaffeinated coffee only contains 3% or less caffeine content. It’s difficult to find decaffeinated coffee that’s 100% caffeine-free. The exact amount of caffeine in your decaf coffee depends on the decaffeination method that’s used.
Common Characteristics in Decaffeination Processes
Before looking at the different decaffeination methods, let’s take a look at common characteristics that you’ll find in all the methods.
- In all the decaffeination methods, coffee beans are decaffeinated while in their green or unroasted state
- One of the greatest challenges involving all the methods is removing caffeine in the coffee beans without interfering with the other compounds in them. This is a challenge because coffee beans contain around 1000 chemical compounds that affect the taste and aroma of your cup of joe
- Water always plays a huge role in the decaffeination methods as a result of its caffeine’s water solubility
- All the decaffeination methods use a mixture of decaffeinating agents and water since water by itself isn’t a good solution for the process. When water alone is used for decaffeination, it will remove other soluble substances such as sugars and proteins that affect the taste of your decaf coffee. Decaffeination agents such as methylene chloride, ethyl acetate, activated charcoal, and carbon dioxide will help minimize the washed-out substances and speed up the entire process
Methods of Decaffeination
There are four methods of decaffeination that are used to date. These methods can be grouped into two categories that include:
- Solvent-based methods
- Non-solvent-based methods
Solvent-based methods involve the removal of caffeine from the coffee beans using the help of chemical solvents such as ethyl acetate and methylene chloride. The solvent-based methods are further divided into two groups. These are:
- Direct methods
- Indirect methods
The direct methods involve removing caffeine from the coffee beans by soaking them directly into the solvents. On the other hand, the indirect method involves transferring caffeine-laden water into a separate tank where it’s treated with solvents. In this method, the coffee beans don’t come into direct contact with the solvents.
Solvents Used in Decaffeination
As mentioned earlier, the decaffeination process involves the use of solvents since water alone will remove other soluble compounds in the coffee beans that are important for the taste and aroma of decaf coffee. The two commonly used decaffeinating agents are ethyl acetate and methylene chloride. Solvents such as benzene, dichloromethane, trichloroethylene, and chloroform haven’t been in use as a result of their toxicity.
Ethyl acetate is considered the most natural method compared to methylene chloride since it exists in ripening fruits such as blackberries and apples. The solvent occurs in nature and so, coffee beans that have been decaffeinated using the method are labeled as naturally decaffeinated. Let’s look at the direct and indirect methods.
The direct method of decaffeinating coffee beans involves steaming the coffee beans for approximately 30 minutes to open up their pores. Once the coffee bean pores have opened, they are rinsed repeatedly using the solvents (methylene chloride or ethyl acetate) to remove the caffeine. The rising process takes about 10 hours. After 10 hours, the solvent is drained away and the coffee beans are steamed to remove any remaining solvent.
This decaffeinating method involves soaking coffee beans in water that’s nearly boiling for several hours to remove caffeine as well as other compounds in the beans such as oils and flavor elements. The caffeine-laden water is then separated from the coffee beans and methylene chloride is added to the water. After this, the caffeine-laden water with methylene chloride is heated to remove the caffeine through evaporation. Once the caffeine is removed, the coffee beans are reintroduced into the liquid where they absorb the oils and flavors that they had initially lost. This way, the coffee beans never come into direct contact with the solvents.
There are two methods involved in the non-solvent category. They include:
- The Swiss Water Method
- The Carbon Dioxide Method
The Swiss Water Method
The Swiss water process of decaffeination involves water and carbon filtration. No chemicals are involved to extract the caffeine. The Swiss water process relies on two concepts, which are osmosis and solubility. For this method, you begin by soaking coffee beans in hot water to dissolve caffeine and other flavorful compounds. The water is then separated from the coffee beans and passed through an activated charcoal filter that filters the larger caffeine molecules while enabling the passage of flavor molecules and smaller oils. The caffeine-free and flavorless coffee beans are then discarded, while the flavor-rich water known as “Green Coffee Extract” remains for later use.
The green coffee extract is used to remove caffeine from a new batch of coffee beans. Since the extract already contains the oils and flavors from the previous coffee beans, the flavors in the fresh beans cannot dissolve in it. Therefore, only caffeine moves from the fresh coffee beans into the green coffee extract. The result is decaffeinated coffee beans that are still flavorful. The Swiss water method is mainly used to decaffeinate organic coffee beans.
The Carbon Dioxide Method
As the name suggests, the supercritical carbon dioxide decaffeination method involves the use of carbon dioxide under high pressure and temperature to act as both liquid and gas. The method involves soaking coffee beans in water to expand their cell structures and to make it easy to extract caffeine. After the beans are soaked, they’re exposed to carbon dioxide for ten to twelve hours at a pressure of 73 to 300 atmospheres. At this pressure, the carbon dioxide acts as a solvent and dissolves the caffeine from the beans leaving the flavor components behind. The carbon dioxide containing caffeine is then transferred to an absorption chamber to remove caffeine and return carbon dioxide to its gaseous state. The carbon dioxide method is mainly used to decaffeinate large amounts of coffee beans since it’s costly.
Pros and Cons of Decaffeinated Coffee
- Contains less caffeine thus ideal for caffeine-sensitive people who still want to enjoy the coffee taste
- No side effects of coffee such as headache, withdrawal, insomnia, or heart palpitations
- Contains antioxidants that help prevent disease and fight free radicals
- The chemical treatments used may leave a bitter or artificial aftertaste
- Decaf coffee may have a higher fat content, thus contributing to elevated cholesterol levels in your body
Decaf coffee is ideal for caffeine-sensitive people or people who’re looking to limit their caffeine intake. Furthermore, decaf coffee won’t give you sleepless nights and you don’t have to experience the caffeine withdrawal symptoms such as headaches and insomnia. If you’re worried about the chemicals involved during the decaffeination processes, stick to decaf coffee beans that are labeled organic. On the other hand, opt for regular coffee if you’re looking to boost your energy levels. Otherwise, the caffeine content in decaf coffee isn’t enough to give you energy.