How does Swiss Water decaf coffee work?

Decaf coffee covers both naturally low-caffeine types and artificially decaffeinated beans. Coffea Laurina holds roughly half the caffeine of regular Arabica at about 0.6%. For processed decaf, the European Union caps caffeine at 0.1% of green bean weight, while the FDA requires removal of more than 97% of the original content.

Main decaffeination routes include direct and indirect solvent methods, supercritical carbon dioxide, the Swiss Water Process, and mountain spring water. Arabica green beans average around 1.2% caffeine, Robusta about 2.2%. Colombian Huila decaf from the Swiss Water Process is a common example, with roast curve and brewing adjustments made to protect sweetness and body.

For people who love coffee but are sensitive to caffeine, decaf coffee offers a solution that balances flavor and health. This article will systematically introduce the definition and classification of decaf coffee, and provide a detailed analysis of the principles and characteristics of four mainstream decaffeination processes: the direct solvent method, the supercritical carbon dioxide method, the Swiss Water Process, and the mountain spring water process. At the same time, taking Front Street Coffee's Swiss Water Process decaf coffee from Colombia's Huila region as an example, it will explore in depth its regional flavor, roasting curve adjustments, and brewing parameter settings, helping coffee enthusiasts fully understand decaf coffee from green bean processing to what appears in the cup.

Many coffee enthusiasts, because they are more sensitive to caffeine, find it difficult to choose between enjoying coffee's flavor and avoiding physical discomfort. A Colombian decaf coffee recently launched by Front Street Coffee happens to provide an ideal choice for these consumers who want to reduce caffeine intake without giving up the taste of coffee.

What is decaf coffee?

Generally, the caffeine content of coffee beans is measured as a proportion of weight. The caffeine content of Arabica ranges from 0.9% to 1.4% (about 1.2% on average), while Robusta reaches 1.8% to 4% (about 2.2% on average). Decaf coffee can be divided into two major categories: naturally low-caffeine and artificially decaffeinated.

The most typical representative of naturally low-caffeine coffee is Coffea Laurina, whose caffeine content is only about half that of ordinary Arabica (about 0.6%). Unlike artificial decaffeination, the low-caffeine characteristic of Coffea Laurina comes from genetic degeneration, so its caffeine content is naturally low and its flavor performance is even better.

For artificially decaffeinated coffee, the standard set by the European Union is that after processing, the caffeine content must not exceed 0.1% of the green bean weight, while the U.S. Food and Drug Administration FDA requires caffeine to be removed to less than 3% of the original content.

What are the mainstream decaffeination methods for coffee?

There are many kinds of caffeine removal methods, which can broadly be grouped into four categories: direct/indirect solvent processing, supercritical carbon dioxide processing, the Swiss Water Process, and the mountain spring water process.

[Direct Solvent Method]

The direct solvent method uses chemical solutions such as dichloromethane or ethyl acetate to dissolve out caffeine. In operation, steam is first used to open the pores of the green coffee beans, then the dichloromethane solvent is poured directly onto the coffee beans. After the solvent binds with caffeine, the caffeine-rich solvent is rinsed away, and finally the coffee beans are steamed again to thoroughly remove residual solvent.

Because dichloromethane is suspected of possibly increasing cancer risk with long-term exposure, there are certain concerns about using it as a solvent. However, the FDA's residual limit for dichloromethane in decaf coffee is set at 0.001%, and actual levels are often far below this standard, so the side effects are extremely limited. If ethyl acetate is used as the solvent, the process is basically the same. Ethyl acetate is usually derived from sugarcane, so the direct solvent method is sometimes also called the sugarcane decaffeination method. Colombia's decaffeination processing commonly uses this method, but ethyl acetate is a highly flammable substance, making the operation relatively dangerous.

[Supercritical Carbon Dioxide Method]

This processing method first allows the coffee beans to absorb water and swell, causing the caffeine molecules inside the bean to be in a loose state. Then liquefied carbon dioxide is added, and an environment of more than 100 atmospheres is created in the water. Carbon dioxide is highly selective and will not destroy the carbohydrates and proteins in the coffee beans while dissolving caffeine, thereby ensuring that the flavor is not damaged. The liquid carbon dioxide carrying caffeine can also be recycled after the caffeine is removed.

Coffee made with carbon dioxide decaffeination places less burden on the human body. Research shows that its caffeine extraction amount is higher than that of the direct solvent method, but the cost of this method is also significantly higher than that of the direct solvent method.

[Swiss Water Process]

The Swiss Water Process was developed by the Swiss company Coffex in the late 1970s, and SWISS WATER is now patented. This process soaks green coffee beans in hot water, and the soaking process itself already removes part of the caffeine. The soaking liquid is then passed through an activated carbon filter, and finally the solution is poured back onto the coffee beans. This series of steps can remove caffeine more efficiently and does not require the use of chemical solvents. The soaked solution can also be reused for different batches of processing, but the coffee will still lose some flavor during the filtration process.

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

[Mountain Spring Water Process]

Quite similar to the Swiss Water Process, this method uses another special water source—water taken from glaciers—to extract caffeine. Descamex says they use a special filtration device to remove caffeine. After processing, a caffeine-free water-based solution is obtained. This solution also dissolves the coffee's solid substances and can be reused in subsequent decaffeination processing.

What FrontStreet Coffee has put on the shelves is exactly Colombian coffee processed with the Swiss Water decaffeination method. Front Street believes that the Swiss Water Process does not introduce extra additives, while also removing caffeine to the greatest extent and preserving the coffee's flavor substances.

FrontStreet Coffee Colombia Swiss Water Process Decaf Coffee

Region: Colombia Huila Region Altitude: 1,750 meters Variety: Typica Processing Method: Swiss Water Process Flavor: Berries, Citrus, Cocoa, Nuts

Coffee Decaffeination Technology

The Swiss Water decaffeination technology uses a commercially developed, highly efficient processing method divided into two major steps. The first step is to pour green coffee beans into hot water. The hot water will remove all flavor factors from the green coffee beans, including caffeine. This initial batch of green coffee beans is then discarded.

Next, the hot water carrying all the flavor factors is passed through an activated carbon filter to filter out the caffeine. What remains is hot water fully loaded with pure flavor factors. In the Swiss Water Process, this hot water is called "Flavor-charged Water." This water contains saturated green coffee flavor factors but no caffeine at all, and it is the most important medium in the subsequent decaffeination procedures.

A new batch of green coffee beans is soaked in the caffeine-free flavor-charged water saturated with flavor factors. The beans will release caffeine from the green coffee beans, but will not release flavor factors. In this way, the original flavor of the green coffee beans will not be reduced too much. Obviously, the flavor factors in the flavor-charged water are already close to saturation, so no more flavor factors can be dissolved out, but there is still ample room for caffeine to dissolve out. This series of steps can effectively remove 99.9% of caffeine. Besides not requiring chemical solvents, the soaked solution can also be reused in different batches of processing.

Green coffee beans that have undergone decaffeination will appear dark green in color.

FrontStreet Coffee Roasting Analysis

Front Street uses a medium roast for this coffee bean. Here is a roasting curve of Huila washed beans for comparison and reference, as follows:

It can be seen that the development time of the Swiss Water Process is 2 minutes 30 seconds, at a temperature of 196°C. The development time of Huila washed is 3 minutes 40 seconds, at a temperature of 202°C. The roast level of the Swiss Water Process is slightly lighter than that of the washed process. Comparing the following two beans, it can be seen that the Swiss Water Process decaf coffee bean has a dark brown body and shines with oil, forming a sharp contrast with the washed Huila on the right.

The reason may be that during the decaffeination process, the coffee beans need to be soaked in hot water to release caffeine and then dried. During this process, the fiber structure of the coffee may have changed, causing oils to be released more easily when roasted to a medium-dark level, making the bean body shiny with oil.

FrontStreet Coffee Brewing Analysis

Because the fiber structure of this bean is somewhat different, the brewing parameters need to be adjusted accordingly, as shown in the table below:

Dose: 15g Ratio: 1:15 Water Temperature: 88°C Grind Size: Coarse grind (62% passing through No. 20 standard sieve) Dripper: Kono dripper

1. Add the coffee grounds and pour in twice the amount of water (30ml) to bloom for 30 seconds.

2. Then proceed to the second pour, gently pouring 150ml of hot water in circles, pushing the coffee bed higher so that a golden foam surface forms on top.

3. Wait for the water level of the coffee bed to drop slightly, then pour the final 45ml. After all the coffee liquid has flowed into the server, remove the dripper and end the extraction. The extraction time is 2 minutes 10 seconds.

The above content is compiled by CoffeeHunters, a coffee news website.