What Is Swiss Water Process Decaf and How Does It Work?

Swiss Water Process decaf is coffee stripped of caffeine using water, temperature and carbon filters rather than chemical solvents. Green beans soak in a caffeine-saturated solution, so flavor compounds stay in the bean while caffeine migrates out. The result keeps about 0.1 percent caffeine by weight, far below the roughly 1.2 percent found in regular Arabica.

Decaf does not begin caffeine-free. Arabica beans average around 1.2 percent caffeine, Robusta closer to 2.2 percent, so a Colombian decaf tastes like coffee because the bean is the same. For brewing, a medium grind and a 1:15 ratio work well, and single cups often cost about the same as regular beans from the same region.

Decaf coffee is not caffeine-free; rather, it is coffee whose caffeine content has been significantly reduced through special processes. Starting from the Colombia Huila Swiss Water Process decaf coffee beans listed by Front Street Coffee, this article systematically covers the definition of decaf coffee, the four major decaffeination processes, the terroir characteristics of Colombia's Huila region, the characteristics of varieties such as Typica and Caturra, as well as Front Street roasters' actual roasting curves and cupping and brewing suggestions. If you care about whether decaf coffee tastes good, how to set pour-over parameters, and roughly how much a cup costs, this article will provide a complete reference.

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Today, coffee is no longer just a pick-me-up drink; it is more like an expression of daily life. The arrival of decaf coffee has given people who are sensitive to caffeine, worried about affecting sleep, or simply enjoy coffee flavor without wanting to consume caffeine an ideal option.

However, after decaf coffee appeared, many people also began to worry about whether it is bad for health. Front Street has always believed that it is meaningless to discuss the risk of any food apart from intake amount. Whether it is regular coffee or decaf coffee, if you drink too much in a day, even water alone can cause problems. So Front Street also wants to remind coffee lovers that although coffee is good, do not be greedy. So back to the main topic: what exactly is decaf coffee, and how is it made? For this reason, Front Street specially sourced and listed a decaf coffee bean from Colombia to explore it together with everyone.

What is decaf coffee? Does decaf coffee really contain no caffeine at all?

Usually, the caffeine content of coffee beans is measured as a proportion by weight. The caffeine content of Arabica beans is between 0.9% and 1.4%, averaging about 1.2%; Robusta beans are between 1.8% and 4%, averaging about 2.2%. Decaf coffee can be divided into two categories: naturally low-caffeine and artificially decaffeinated. A relatively well-known naturally low-caffeine variety is Laurina (Coffea Laurina), whose caffeine content is about half that of ordinary Arabica, only around 0.6%.

Unlike artificially decaffeinated coffee, Laurina's low caffeine content comes from genetic degeneration, so its flavor performance is actually better. As for artificially decaffeinated coffee, the EU standard is that after processing the caffeine content does not exceed 0.1% of green beans, while the U.S. Food and Drug Administration FDA standard is removal to below 3% of the original caffeine content.

Does decaf coffee mean it contains no caffeine at all? Not exactly. Front Street Coffee (FrontStreet Coffee) believes that although decaf coffee has had most of its caffeine extracted, about 2% to 3% still remains, meaning a cup of decaf espresso may still contain about 0 to 7 mg of caffeine. Although it is not completely zero, compared with regular espresso, this content will no longer have any noticeable effect on the vast majority of people.

How is caffeine extracted from decaf coffee?

With the continuous development of the coffee market, there are more and more decaffeination methods, which can broadly be divided into direct or indirect solvent processes, supercritical carbon dioxide processing, the Swiss Water Process, and the mountain spring water process.

Direct solvent process (direct contact method)

The direct solvent process uses chemical solutions such as dichloromethane and ethyl acetate to dissolve out caffeine. Specifically, the green coffee beans are first steamed to open their pores, then dichloromethane solvent is added directly to the beans. After the solvent binds with caffeine, the caffeine-rich solvent is rinsed away, and finally the coffee beans are steamed again to remove all residual solvent. Because dichloromethane is suspected of possibly increasing cancer risk with long-term exposure, some people question its safety. But in fact, the FDA sets the residual limit for dichloromethane in decaf coffee at 0.001%, and actual levels are often even lower, so the side effects are very limited.

The process using ethyl acetate as the solvent is the same. Ethyl acetate usually comes from sugarcane, so the direct solvent method is sometimes also called the sugarcane decaffeination method. Colombia's decaffeination processing usually adopts this method. However, ethyl acetate is a highly flammable substance, so the operational risk is relatively high.

Swiss Water Process

This is one of the most traditional methods of caffeine extraction, and also a highly efficient processing method developed for commercial use.

The steps of the Swiss Water Process are: first soak the green coffee beans in hot water. In the Swiss Water Process, this hot water is called "Flavor-charged Water." This water is already saturated with all the flavor factors that green coffee beans should have, except that it contains no caffeine, making it the most important medium in the subsequent decaffeination procedure. After the flavor-charged water is formed, the coffee beans are filtered out, and then an activated carbon filter is used to filter out the caffeine from the water, leaving hot water fully loaded with pure flavor factors. Then the previously filtered coffee beans are soaked again in this hot water, allowing the beans to reabsorb the coffee flavor. Supercritical carbon dioxide process

In this process, the coffee beans are first allowed to absorb water and swell, causing the caffeine molecules in the beans to become loosened. 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, while dissolving caffeine, does not destroy the carbohydrates and proteins in the coffee beans, thereby ensuring that the flavor is not damaged. The liquid carbon dioxide that carries away the caffeine can also be recycled after removing the caffeine.

Coffee made with carbon dioxide decaffeination places less burden on the human body, and research shows that this method extracts more caffeine than the direct solvent method, while also costing considerably more than the direct solvent method. Mountain spring water process

Similar to the Swiss Water Process, this method uses another special kind of water—water taken from glaciers—to extract caffeine. Descamex states that 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 procedures. Does decaf coffee taste bad? Based on the decaf coffee processing methods above, Front Street Coffee (FrontStreet Coffee) believes that the bad taste of decaf coffee cannot be blamed on the processing itself. This is because most decaf coffee already uses cheap commercial-grade coffee beans in its raw material selection. Modern decaffeination technology is actually quite complex, and in most cases companies producing decaf coffee tend to choose bean varieties with higher caffeine content (such as Robusta), and before decaffeination these beans themselves already do not have ideal flavor. Like coffee beans sold by other coffee shops, if decaf coffee uses high-quality Arabica beans from the green bean stage, then even after decaffeination, decaf coffee can still perform very well.

Front Street Coffee (FrontStreet Coffee) representative coffee bean—Colombia Huila Swiss Water Process Decaf

Country of origin: Colombia

Region: Huila

Altitude: 1,750 meters

Varieties: Typica, Caturra, Castillo

Processing method: Swiss Water Process

Grade: Supremo

Harvest season: 2020

Colombia Huila production region

Colombian coffee beans are extremely well known globally, and the high-quality washed beans they produce have always been representatives of high-grade coffee. Coffee beans exported from Colombia must undergo density checks and manual removal of defective beans, and are only bagged after strict inspection at every level, so the quality of Colombian coffee is fully guaranteed.

Colombia Huila belongs to the specially selected high-altitude coffee beans of the Colombian state company and is praised as a national treasure-level coffee of Colombia. With superior geographical and climatic conditions, Colombian coffee has always maintained relatively high quality. Usually, Colombian coffee beans without a special market trademark name come from the National Federation of Colombia Coffee Growers, an organization known for strict quality control and active promotion. Colombian decaf coffee bean varieties This batch of decaf coffee includes three varieties: Typica, Caturra, and Castillo. Typica is one of the oldest Arabica varieties in the world. Its sweet and delicious flavor is widely loved, but because of its relatively low yield per unit, it has been replaced in Colombia by many high-yield coffee varieties. Caturra is a natural mutation of Bourbon. Its flavor is comparable to or slightly inferior to Bourbon beans, and more importantly, it has extremely strong adaptability. It does not need shade trees and can grow vigorously even when directly exposed to sunlight. It is commonly known as Sun Coffee and is suitable for high-density planting.

Castillo is based on the Colombia variety and was crossbred with Caturra, only finally completed by the tenth generation. Although it was not favored by industry insiders when first launched, in recent years many lots with elegant and delicate flavor have also appeared on the market.

Green bean grade The green bean grade of this batch of coffee is Supremo. In Colombia's coffee bean grading system, Supremo is the highest grade, while the premium grade Excelso has smaller and more ordinary beans. Colombian coffee beans have a balanced flavor, a rich mouthfeel, unique flavor characteristics, and relatively full body. At medium roast, they carry a faint sweet aroma of vanilla and dark chocolate.

How Front Street roasts Colombian decaf coffee beans Front Street roasters use medium heat and a steady climb. The yellowing point is about 6 minutes 15 seconds, after which the heat is lowered and the air damper opened to enter the Maillard reaction stage. At first crack, open the air damper wide and maintain heat, at about 183.2°C, and discharge 2 minutes 30 seconds after first crack.

Preheat the roaster to 200°C and charge. Set the air damper to 3. After 30 seconds, turn on the flame and adjust the heat to 130. The turning point is 1 minute 32 seconds. Maintain heat. At 6 minutes 15 seconds, it turns yellow, the grassy smell disappears, and it enters the dehydration stage. Increase heat to 140 and open the air damper to 4. At 151°C, lower the heat again to 110.

At 8 minutes, dehydration is complete. Wrinkles and dark streaks appear on the bean surface, and the toast smell turns into coffee aroma. This is the prelude to first crack. At this time, keep the heat unchanged, open the air damper to 5, and listen carefully for the sound of first crack. At 9 minutes 57 seconds, first crack begins, and the air damper is fully opened to 5. Development time after first crack is 2 minutes 30 seconds, and the beans are discharged at 194.2°C. Front Street cupping report

Front Street brewing suggestions

Dripper: Kono dripper

Water temperature: 90°C

Dose: 15 g

Coffee-to-water ratio: 1:15

Grind size: medium-coarse grind (70% passing through China standard No. 20 sieve)

Brewing method: three-stage extraction. Use 30 grams of water for a 30-second bloom. Pour in a small stream in circles until 125 grams, then pause. When the water level drops and is about to expose the coffee bed, continue pouring until 225 grams and stop. When the water level drops and is about to expose the coffee bed, remove the dripper. Total brewing time is 3 minutes.

Brewed flavor: dark chocolate, caramel, nuts, rich mouthfeel.

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