What is Decaf Coffee: Colombian Decaf Coffee Bean Origin, Flavor Characteristics, and Processing Methods

Many coffee lovers often find themselves in a dilemma due to caffeine intolerance. FrontStreet Coffee recently launched a Colombian decaf coffee, bringing good news to those who want to enjoy the delicious taste of coffee without consuming excessive caffeine.

What is Decaf Coffee?

Typically, the caffeine content of coffee beans is measured by weight ratio. Arabica coffee beans contain 0.9%-1.4% caffeine (averaging 1.2%), while Robusta contains 1.8%-4% (averaging 2.2%). Decaf coffee is divided into naturally low-caffeine coffee and artificially processed decaffeinated (low-caffeine) coffee.

The most common naturally low-caffeine coffee is Laurina Bourbon (Coffea Laurina), which has half the caffeine content of regular Arabica (0.6%). Unlike other artificially processed decaf coffees, Laurina Bourbon has genetically degenerated, resulting in lower caffeine content compared to typical Arabica coffee trees, with superior flavor.

For artificially processed decaf coffee, the EU standard for such decaf coffee is that the processed caffeine content should not exceed 0.1% of green beans, while the US FDA standard requires reduction to less than 3% of the original caffeine content.

What are the Common Decaf Coffee Processing Methods?

There are many methods for removing caffeine, which can be broadly divided into direct/indirect solvent processing, supercritical carbon dioxide processing, Swiss water processing, and mountain spring water processing.

Direct Solvent Processing

Direct solvent processing uses chemical solutions such as dichloromethane and ethyl acetate to dissolve caffeine. First, steam opens the pores of green coffee beans, and dichloromethane solvent is added directly to the coffee beans. After the solvent and caffeine combine, the caffeine-filled solvent is washed away, and the coffee beans are steamed again to remove all residual solvent.

Since dichloromethane is suspected to increase cancer risk with long-term exposure, there are concerns about its use as a solvent. However, the FDA limits the dichloromethane content in decaffeinated coffee to 0.001%, which is actually lower than this, with minimal side effects. The process using ethyl acetate as a solvent is the same; ethyl acetate typically comes from sugarcane, so when used, the direct solvent method is sometimes called the sugarcane decaffeination method. Colombian decaffeination usually uses this method. However, ethyl acetate is highly flammable, making it more dangerous.

Supercritical Carbon Dioxide Processing

This processing method first allows coffee beans to absorb water and expand, with caffeine molecules in a loose state within the beans. Liquefied carbon dioxide is added and creates pressure greater than 100 atmospheres in water. Carbon dioxide is highly selective, dissolving caffeine without "damaging" the carbohydrates and proteins in the coffee beans, ensuring that the flavor of the coffee beans is not destroyed. The liquid carbon dioxide that has carried away the caffeine can also be recycled after removing the caffeine.

Coffee decaffeinated using carbon dioxide places less burden on the human body, and according to research, this method extracts more caffeine than the direct solvent method, although the cost of this method is much higher than the direct solvent method.

Swiss Water Processing

Swiss Water Processing was developed by the Swiss company Coffex in the late 1970s, and SWISS WATER is currently a registered patent. This processing method soaks green coffee beans in hot water. During the soaking stage, caffeine is partially removed. The soaked solution is then filtered with activated carbon, and finally, the solution is poured back into the coffee beans. This series of steps more effectively removes caffeine. Besides not requiring chemical solvents, the soaked solution can also be reused in different batch processing procedures, but the coffee still loses flavor during the filtration process.

The caffeine removal rate of this method can reach 99.9%, making it the method with the highest caffeine removal rate.

Mountain Spring Water Processing

Very similar to Swiss Water processing, this uses another special water, taken from glacial water, to extract caffeine. The company Descamex states that they use a special filtration device to remove caffeine. After processing, a water-based solution without caffeine is obtained, which also dissolves the solid substances of coffee and can be reused in the decaffeination process.

FrontStreet Coffee offers Colombian Swiss Water processed decaf coffee. FrontStreet Coffee believes that Swiss Water processing does not apply unnecessary additives and can maximize caffeine removal while preserving coffee flavor compounds.

FrontStreet Coffee Colombian Swiss Water Decaf Coffee

Region: Colombian Huila Region
Altitude: 1750 meters
Variety: Typica
Processing Method: Swiss Water Processing
Flavor: Berry, Citrus, Cocoa, Nut

Coffee Decaffeination Technology

Swiss Water decaffeination technology uses a commercially developed high-efficiency processing method with two main steps. The first step involves pouring green coffee beans into hot water, at which point the hot water removes all flavor factors from the green coffee beans, including "caffeine," and this initial batch of green coffee beans is discarded.

Then, the hot water loaded with all flavor factors is filtered through activated carbon to remove caffeine, leaving behind hot water full of pure flavor factors. This water is called "Flavor-Charged Water" in the Swiss Water processing method. This water contains saturated flavor factors from green coffee beans but lacks caffeine, making it the most important medium in the decaffeination process.

A new batch of green coffee beans soaked in flavor-factor-rich, caffeine-free Flavor-Charged Water will release the caffeine from the green coffee beans but will not release flavor factors. This way, the original flavor of the green coffee beans will not be significantly diminished. Obviously, the flavor factors in the Flavor-Charged Water are already close to saturation, so they cannot dissolve more flavor factors, but there is still plenty of space to dissolve caffeine. This series of steps effectively removes 99.9% of caffeine. Besides not requiring chemical solvents, the soaked solution can be reused in different batch processing procedures.

After decaffeination processing, the green coffee beans will appear dark green in color.

FrontStreet Coffee Roasting Analysis

FrontStreet Coffee uses a medium roast for these coffee beans. Here, we share a roasting curve of Huila washed beans for comparison:

It can be seen that the development time for Swiss Water processing is 2'30 at 196°C, while the development time for Huila washed is 3'40 at 202°C. The roast degree of Swiss Water processing is slightly lighter than the washed processing. Comparing these two beans, we can see that Swiss Water processed decaf coffee beans are dark brown and oily, which is particularly evident compared to the washed Huila on the right.

The reason may be that during the decaffeination process, coffee beans need to be soaked in hot water to release caffeine, then undergo drying treatment. During this process, the fiber structure of the coffee may have changed, causing oils to be more easily released when roasting reaches medium-dark, making the beans appear oily and shiny.

FrontStreet Coffee Brewing Analysis

Because this bean has a different fiber structure, brewing parameters need to be adjusted, as shown in the table below:

Dose: 15g
Ratio: 1:15
Water Temperature: 88°C
Grind Size: Coarse grind (62% pass rate through #20 standard sieve)
Dripper: Kono dripper

1. Pour in the coffee grounds, inject 2 times the water amount (30ml) and let it bloom for 30 seconds.

2. Then perform the second water injection, gently pouring in a circular motion 150ml of hot water, pushing up the coffee bed to create a golden foam surface.

3. Wait for the water level in the coffee bed to drop slightly, then inject the final 45ml. Remove the dripper after all the coffee liquid has flowed into the lower pot to end extraction. The extraction time is 2 minutes and 10 seconds.

Important Notice :

前街咖啡 FrontStreet Coffee has moved to new addredd:

FrontStreet Coffee Address: 315,Donghua East Road,GuangZhou

Tel:020 38364473