For some regular coffee drinkers, decaf may be a taboo word associated with a lesser cup of coffee, but decaf coffee is far more complicated than watered-down coffee. In this blog, we’ll talk about how decaf coffee beans are made, discuss and compare different decaffeination methods, and explain how these processes influence flavor and aroma.
Popular Decaffeination Methods
In the next section, we’ll talk about some popular decaffeination methods, including Swiss water, the CO2 process, and solvent-based methods.
Swiss Water Method
Also known as the water-processed decaf method, this process is when caffeine is extracted from coffee beans using water through osmosis. The Swiss water method effectively retains the flavor of the beans, and removes 99.9% of the caffeine.
It’s especially popular among health-conscious coffee drinkers as it’s completely chemical-free and more environmentally friendly. The downside is that the finished product can be slightly muted or less intense in flavor if the beans are allowed to age. And it can be more expensive than other methods.
The steps are as follows:
-
Coffee beans are soaked in hot water to “dissolve” the caffeine. Sugars and other flavor compounds in the coffee also dissolve into the water.
-
The resulting mixture is then run through a charcoal filter. Caffeine is a large molecule, so it will get filtered out while the sugars and flavor compounds remain in the water. That is known as the Green Coffee Extract.
-
The next batch of green coffee beans are then soaked in the Green Coffee Extract , retaining the flavor of the beans and only removing the caffeine.
-
The process repeats.
CO₂ Process
During this decaffeination process, green coffee beans are soaked in highly-compressed liquid CO2. It’s a highly efficient method that’s gentle in treating the flavor compounds. This process is commonly used in large-scale decaf production.
The process is as follows:
-
The green coffee beans are soaked in highly compressed liquid CO2.
-
The CO2 draws out only the caffeine from the beans.
-
The caffeine is removed from the CO2 through activated carbon filters.
-
The carbon dioxide returns to its gaseous state, which is contained.
-
The gaseous CO2 is reused to extract caffeine from the next batch.
Solvent-Based Methods
Another category of decaffeination is solvent-based methods, which are the cheapest and fastest processes. The downside is that these methods may also slightly alter flavor, and can have small amounts of dangerous chemicals.
The two types of solvent-based decaffeination are the direct and indirect methods, and they each involve soaking the beans to decaffeinate them. In the direct method, the coffee beans are steamed and soaked directly in food-safe chemicals, while the indirect method is when the water is separated from the beans before they’re treated.
Let’s break down each of these methods in steps:
The Direct Method Steps
-
The coffee beans are steamed and soaked in food-safe chemicals such as ethyl acetate or methylene chloride.
-
The solvent binds to the caffeine and extracts it from the beans
-
After soaking for a set time, the coffee beans are steamed once more to remove chemical residue
The Indirect Method Steps
-
The coffee beans are soaked in hot water
-
The water is then separated from the beans, and a chemical solvent is added.
-
The caffeine bonds to the solvent in the water and evaporates.
-
The caffeine-free water is returned to the beans, absorbing flavors and aromas.
What to Expect in Decaf Coffee
In the next section, we’ll detail what to expect with your decaf coffee including the leftover caffeine in decaf, flavor and aroma changes, and health contexts to keep in mind.
Residual Caffeine Content
Caffeine content levels can also differ depending on your chosen method, bean type, and roast level. For instance, lighter roasts retain slightly more caffeine.
Here are a few facts about decaffeination:
-
The typical decaf coffee contains about 2-15 mg of caffeine per 8 oz cup while a regular cup of coffee has about 70-140 mg of caffeine.
-
Caffeine can have strong effects on highly sensitive drinkers, so the chosen method can be crucial if those individuals even want to drink coffee at all.
-
CO2 and the Swiss Water method remove 99.9% of caffeine
-
Solvent-based decaffeination removes about 97% of the caffeine.
Flavor and Aroma Changes
Decaffeination isn’t an easy process; it requires care to make sure that the coffee beans retain their natural aroma and flavor. Inevitably, decaffeination can remove some aromatic compounds, which can reduce the brightness and complexity of the flavor.
Some decaffeination methods are better than others in keeping the delicate balance. Swiss Water and CO2 processes preserve sweetness, floral notes, and balanced acidity more than solvent-based processes. One can also help restore or mask lost flavors with different roast levels (i.e., darker roasts may cover slight changes,s and lighter roasts can highlight flavor differences).
Health and Safety Notes
The direct and indirect methods have been used for years, but were controversial as the chemicals were mildly carcinogenic in high doses. Other items that include these chemicals include paint stripper, nail polish remover, and degreaser.
Because of this, the United States Food and Drug Administration and other regulatory health bodies have established strict limits on the amount of chemicals present on the finished beans. Modern solvent-based methods have also taken steps to use safer, food-grade chemicals that are removed before the beans are roasted.
For those who want more peace of mind, some coffee companies also emphasize “naturally decaffeinated” or “Swiss Water” on their labels to show that no chemicals were used.
If you’re looking for more high-quality coffee equipment and tools for your natural decaffeinated brew, explore Pesado’s many options.
Choosing Your Perfect Decaf
Many coffeemakers have refined the decaffeination process, but there are individual drawbacks to each of the three main methods: Swiss Water, CO2, and Solvent-Based. Swiss Water is more expensive and can dull the flavor, CO2 is not practical, and solvent-based has its own health and flavor controversies in diluting the bean.
When choosing your decaffeination method, consider your taste preferences, health concerns, and sustainability philosophies. Depending on those inclinations and capabilities, you may more easily adopt a particular method. When it comes to extracting the purest essence and flavor from your roasted, decaffeinated beans, look into the many ergonomically designed tools and high-quality equipment from Pesado.
