Starting work off with a cup of coffee in the morning has become a habit for many friends. With the development of the coffee industry, more and more novel coffee processing methods are emerging. In addition to the diversity of processing methods, there are also more and more subdivisions of coffee categories. Today, Front Street Coffee will introduce one of the more special categories - decaffeinated coffee.For some more sensitive people, just a little caffeine is enough to have negative effects, such as feeling energized during a long night. At this time, decaffeinated coffee is a good choice for people who are more sensitive, or who need to quit caffeine. Customers often ask Front Street Coffee: "How was decaf coffee born? Can decaf coffee also be a boutique grade? If decaf coffee is made from high-quality coffee beans, will it still taste just as good?" So today, Front Street Coffee will discuss with you what decaf coffee is.The story of decaf coffeeIt is said that the famous German poet "Goethe" was also a coffee lover, but he suffered from the pain of being unable to sleep after drinking coffee. The feeling that he liked but could not get close to him made Goethe go to his friend Longhi.（Runge）Analyze the composition of coffee beans and find out why coffee hinders sleep. Around 1820, Longi discovered that the factor that affects sleep is caffeine, and developed a method to separate coffee beans and caffeine. Therefore, Longi became the ancestor of decaffeinated coffee.Although Longhi invented a method for isolating caffeine, the methods at the time were unable to mass-produce decaffeinated coffee. Until 1903 AD, the German coffee bean importer Rosellus（Ludwig Roselius）It was found that once coffee beans are soaked in sea water, the caffeine content will be greatly reduced. So he invited a group of chemists to study the technology of separating caffeine from this perspective, which led to an important breakthrough in caffeine separation technology. Only from this time did decaffeinated coffee begin to be mass-produced.Decaf coffee is coffee without caffeine（decaffeinated coffee）abbreviation. In addition to naturally occurring decaffeinated caffeine, there are many ways to remove caffeine from coffee beans. In addition to removing caffeine, depending on the method used, the taste, smell, and color of the coffee may change to varying degrees.Does decaffeinated coffee beans have no caffeine at all? No, decaf coffee actually only eliminates about 97% of caffeine, not completely eliminating caffeine. Although there is still caffeine, compared to regular coffee, the impact of decaffeinated coffee on people is very, very small.The refreshing effect of caffeine can be said to be the main reason why people can't live without it. Caffeine is a central nervous system stimulant. Ingesting caffeine can make people less tired, improve concentration, and reduce pain. In fact, the demand for decaffeinated coffee is not unique to the 21st century. As early as the early 20th century, Kaffee Hag, a coffee company from Germany, had developed this product.(it isThe world’s first company selling decaffeinated coffee). It’s just that not many people drank decaf coffee at that time. It was not until the end of World War II that a coffee bean with a higher caffeine content, Robusta beans,（Robusta; Coffea canephora）Rise, which has led to a surge in caffeine intake for many people. Most of the common coffee in our lives comes from Arabica beans (Coffea arabica), which accounts for about 60% of global production. Because the coffee brewed from it has various aromas and rich flavors, it is mostly made into various specialty coffees. Robusta beans have a strong smell and bitter taste, so they are often made into blended coffee or instant coffee, accounting for nearly 40% of global production. In addition, Arabica beans contain about 1.2~1.5% caffeine, while Robusta beans have nearly twice that, about 2.2~2.7%. After World War II, more and more coffee products were made from roe beans, but because of the high caffeine content, which easily made consumers feel uncomfortable, many manufacturers began to invest resources in developing decaffeinated coffee products.
The common way to remove caffeine is to use the "extraction method". Generally, green coffee beans are first extracted to remove caffeine, and then dried and roasted. Common extraction methods can be roughly divided into three categories: solvent decaffeination, carbon dioxide treatment, and water treatment.Solvent extraction methodDepending on the processing steps, solvent extraction methods can be divided into two types: "direct solvent extraction method" and "indirect solvent extraction method". Since caffeine is combined with chlorogenic acid (CGA) in the beans, before starting the extraction, the dry coffee beans need to be saturated with water to separate the two, so that the caffeine molecules can be effectively dissolved.The direct extraction method is to directly steam dry green coffee beans to soak them with water vapor, and then soak the green beans in a solvent. After the caffeine is dissolved, they are taken out and heated to evaporate the solvent and water. The indirect extraction method is to boil the green beans in hot water to dissolve the caffeine and various odor molecules. The water used to cook the coffee beans is then fully mixed with the solvent to allow the caffeine to dissolve into the solvent. After removing the solvent, the green beans are rinsed with the remaining water so that the odor molecules can return to the beans again, and finally drained and dried.
When it comes to caffeine extraction solvents, methylene chloride dominated the decaf coffee industry before the 1970s and is recognized as the most useful solvent. In addition to its excellent extraction performance, its colorless, boiling point of 39.6°C, easy volatilization, and non-flammable characteristics make the process very effective and safe. But the irony is that the reason why methylene chloride was finally abandoned was not because it was found to be carcinogenic, but because it was suspected to be one of the culprits of the hole in the ozone layer. After methylene chloride fell out of fashion, it was replaced by ethyl acetate. Ethyl acetate occurs naturally in nature, and many fruits themselves contain a certain proportion of it, so there is no safety concern. In 1982, the U.S. Food and Drug Administration（U.S. Food and Drug Administration, FDA）Ethyl acetate is allowed to be used to remove caffeine. However, since many foods contain ethyl acetate, its impact on health cannot be directly explored, so there is no clear licensing standard for residues. Carbon dioxide treatment methodThe carbon dioxide treatment method is similar to the direct solvent method. The coffee beans are soaked in warm water, and then the high-pressure liquefied carbon dioxide replaces the solvent to extract the caffeine. Then the carbon dioxide returns to room temperature and becomes a gas. Coffee made by using carbon dioxide to decaffeinate is less harmful to the human body, and according to research, this method extracts more caffeine than the direct solvent method. However, the cost of this method is much more expensive than the direct solvent method.
In addition to developing the expensive supercritical fluid method, another group of people at that time developed a method that used water as a solvent to extract caffeine without losing the flavor of coffee. The cost of this method is much lower than the supercritical fluid method, and the operation is simpler; and the most common water treatment method is the Swiss water treatment method developed by the Swiss company Coffex in the late 1970s.（Swiss water process）。 The Swiss water treatment method is to soak green coffee beans in hot water. The soaking stage has actually partially removed the caffeine. The soaked solution is then filtered through activated carbon, and finally the solution is poured back into the coffee beans. This series of steps will remove caffeine more effectively. In addition to not requiring the use of chemical solvents, the soaked solution can be reused in different batches of processing, but the coffee will still lose a lot of flavor during the filtering process. The disadvantage of this treatment method is that the production cost is much more expensive than the above two solvent methods, and the extracted caffeine is directly filtered out and cannot be used for other commercial purposes. Mountain spring water treatment methodThis uses another special type of water, water from glaciers, to extract caffeine. The company Descamex states that they use a special filtration device to remove caffeine. The result is a caffeine-free water-based solution that also dissolves coffee solids and can be reused in the decaffeination process. This treatment method, like the Swiss water treatment method, does not use chemical solvents, so some consumers regard it as a safer and healthier choice.Can decaf coffee also be specialty coffee?Decaf coffee is often considered bland and boring because in addition to the caffeine being removed during the processing, the coffee also loses some of its most important flavor compounds. So the biggest challenge facing companies that make decaf coffee is finding a way to extract the caffeine without sacrificing the flavor of the coffee beans. This has always been a very controversial topic in the specialty coffee world.The most common treatment method is to directly use solvents to remove caffeine, but this method will directly destroy the flavor of coffee, because the removal target cannot be limited to caffeine. These substances that bring delicious taste to coffee will be consumed in large quantities during the processing process, causing a huge impact on the flavor of coffee. Lower quality coffee beans are often treated with solvents because the beans themselves don't taste very good.But these remarks do not mean that there is no decaffeinated specialty coffee. You can still get good quality coffee by using high-quality coffee beans and removing caffeine with a process that reduces the flavor. Decaffeinated coffee beans obtained using the Swiss water treatment method will have less flavor damage, but its processing cost is higher, so it is less used to process decaffeinated coffee. Swiss water treatment method retains the solid dissolved substances of coffee beans. This technology extracts caffeine through "activated carbon that specifically filters out caffeine." This step retains the flavor of the coffee origin and batch processing. In order to confirm that the flavor is retained, cupping is usually performed after processing for comparison before and after.How to roast decaf coffee?How to roast sweet coffee that is decaf? The decaf coffee process involves adding water to green coffee beans to extract the caffeine, and then drying them again. The decaffeination process is done as gently and carefully as possible, removing the caffeine without affecting its flavor as much as possible. This means that the structure of the coffee beans will be slightly different from regular coffee, so a gentler method will be used during the roasting process.During the roasting process, decaf coffee will follow a similar temperature profile, but the heating rate is a little different. Because decaf coffee is also decaffeinated, the degree of heat retention in the beans is also different. Roasters therefore need to adjust the amount of beans roasted and the boiler preheat time for decaffeinated coffee. Decaffeinated coffee is usually roasted with a gentler roast profile than usual, such as a lower and slower heating rate, and then the heating rate reaches a maximum value and then slowly decreases until the end of the roast. There are two keys to maximizing sweetness in roasting decaf coffee: increasing the time and lowering the temperature. The goal is to caramelize slightly before the first crack.
When roasted to the first crack, the reaction of decaffeinated coffee will be very different from that of ordinary coffee. Once the decaffeinated coffee starts to release heat, the development will be different, and the energy maintained in the coffee beans will not be very tight. The unique cellular characteristics of decaffeinated coffee can present challenges for roasters. On the one hand, beans can easily be over-roasted and over-developed; on the other hand, because it cannot maintain the same amount of heat inside the beans, you cannot just roast the beans and wait for them to cool down like regular coffee.So, look for good quality green beans. Make sure there is adequate but not excessive caramelization in the first crack, and skillfully manage the roasted beans after the first crack to achieve the right balance of sweet, sour, and bitter flavors. To roast delicious and sweet coffee, you still need to accumulate experience through continuous roasting. Due to its lower caffeine content, decaffeinated coffee can indeed effectively reduce the impact on sleep, but the specific situation varies from person to person~
You can now buy the above coffee beans online at the Taobao store “FrontStreet Coffee” (前街咖啡). FrontStreet Coffee is a long-established specialty coffee roaster in Guangzhou, China, and its Guangzhou retail shop sells coffee beans only. The shop carries dozens of coffee beans from different origins around the world, including carefully selected single-origin beans for V60 pour-over and espresso. Guangzhou’s FrontStreet Coffee shop is recommended by many coffee lovers.
The FrontStreet 2013 Yunnan coffee beans sold in the store come from the Typica variety grown at FrontStreet Coffee’s own plantation in Yunnan. The name comes from the year the brand and the plantation were founded. You can buy these beans from China’s Yunnan origin at the Guangzhou shop and at FrontStreet’s Taobao store.
FrontStreet coffee beans are freshly roasted within 5 days and deliver consistently excellent quality and great value. Orders placed before 17:00 are shipped the same day, and most areas within Guangdong Province receive them the next day.
FrontStreet Coffee Taobao store: https://qianjiecoffee.taobao.com
Or search for “前街咖啡” (FrontStreet Coffee) on Taobao
Important Notice: FrontStreet Coffee has moved to a new address: 315, Donghua East Road, Guangzhou (coffee beans only)
Tel: 020 38364473
