When we drink coffee, we usually use coffee beans with normal caffeine content. However, there are some people who are extremely sensitive to caffeine and may be so energized by the intake of some that they are unable to sleep. Others may be accompanied by heart palpitations and rapid heartbeat, but they have to drink it because they need a pick-me-up.
Therefore, in order not to delay the quality of their sleep at night, to reduce the feeling of discomfort should reduce the amount of caffeine intake. This has led to the demand for decaffeinated coffee.
Decaffinated Coffee
The low-caffeine coffee we often talk about should strictly be called decaffeinated coffee, which is called Decafe in English, and it is wrong to call it decaffeinated coffee because there is no way to remove 100% of the caffeine according to the current technology.
As mentioned before, the caffeine content of Arabica is generally around 0.9% – 1.4%, while the caffeine content of Robusta is generally around 1.7% – 3.0%. With decaffeinated coffee, about 97% of the caffeine is removed during the production process compared to regular coffee beans.
How did decaffeinated coffee come about?
The first commercially successful decaffeination process was invented in 1903 by German businessman Ludwig Roselius and his colleagues, when Roselius overheard a batch of raw coffee beans soaked in seawater, which had become very low in caffeine without any loss of flavor. 1906 saw the patenting of this process, which essentially involved The process was patented in 1906 and consisted of steaming the beans with various acids or bases and then using benzene as a solvent to remove the caffeine. Coffee decaffeinated in this way was sold under the company name Kaffee Handels-Aktien-Gesellschaft (Coffee Trading Company) as Kaffee HAG in much of Europe, Café Sanka in France, and later under the Sanka brand of coffee in the U.S. Café HAG and Sanka are now Kraft Foods global brands. are global brands of Kraft Foods.
Existing methods are almost always based on the same approach, in which raw coffee beans are first soaked and washed, usually with water, organic solvents or carbon dioxide, during which the caffeine is dissolved and then precipitated in combination with other substances, resulting in decaffeinated coffee beans that are then roasted.
Mainstream decoupling methods include: solvent extraction, Swiss water treatment, and carbon dioxide extraction.
Solvent Extraction
Before scientists have a clear understanding of the effects of various solvents on the human body, many solvents that are now considered to have health concerns or carcinogenic risks have been used by manufacturers to extract caffeine, including benzene, chloroform and carbon tetrachloride, etc. However, the most common solvents are methylene chloride and ethyl acetate. However, the most common extraction solvents are methylene chloride and ethyl acetate.
According to the different processing steps, solvent extraction can be divided into “direct solvent extraction” and “indirect solvent extraction”. Because caffeine is combined with chlorogenic acid (CGA) in the beans, it is necessary to separate the two by saturating the dry coffee beans with water before extraction begins in order to effectively dissolve the caffeine molecules.
Direct Extraction
Directly steam the dry raw coffee beans, then soak the beans in a solvent to dissolve the caffeine, and then remove and heat the solvent and water to evaporate.
Indirect Extraction Method
Raw beans into the hot water to boil, dissolve caffeine and various odor molecules, the water used to boil the coffee beans and then mixed with the solvent, so that the caffeine dissolved into the solvent, remove the solvent and then use the remaining water to rinse the raw beans so that the odor molecules can be returned to the beans, and then finally leaching, drying.
When it comes to caffeine extraction solvents, methylene chloride dominated the low-caffeine coffee industry until the 1970s, and is widely recognized as the best solvent to use. In addition to the extraction results are quite good, its colorless, boiling point of 39.6 ℃, easy to volatilize, and is not easy to burn the characteristics of the process is quite effective and safe.
The U.S. Food and Drug Administration (FDA) limits the amount of methylene chloride in decaffeination to 10 parts per million (0.001%). Studies have since found that prolonged exposure to methylene chloride is suspected to increase the risk of cancer, so there are some concerns about the use of this solvent.
When methylene chloride was withdrawn from history, it was replaced by ethyl acetate. Ethyl acetate occurs naturally in nature, and many fruits contain a percentage of it, making it less of a safety concern. In 1982, the U.S. Food and Drug Administration (FDA) licensed the use of ethyl acetate for caffeine removal, but because it is found in so many foods, there is no way to directly address its health effects, so there is no clear indication of its use. However, because ethyl acetate is found in many foods, its health effects cannot be directly addressed, and therefore there are no clear residual licensing standards.
Supercritical carbon dioxide extraction (Supercritical CO2 process)
The carbon dioxide (CO₂) method is a relatively new extraction method. Developed by Max Plank Institute scientist Kurt Zosel, it uses liquid carbon dioxide instead of a chemical solvent. It acts selectively on caffeine, meaning that it only releases alkaloids and nothing else.
In the CO2 decaffeination process, coffee beans soaked in water are placed in a stainless steel container called an extraction vessel. The extractor is then sealed and liquid carbon dioxide is injected into the coffee at 300 atmospheric pressure to extract the caffeine.
Carbon dioxide acts as a solvent to dissolve and absorb the caffeine from the coffee beans, leaving behind the larger molecules of flavor components. The caffeine-containing carbon dioxide is then transferred to another vessel called the absorption chamber. Here, pressure is released and the carbon dioxide returns to a gaseous state, leaving behind the caffeine. The decaffeinated carbon dioxide gas is pumped back into the pressurized vessel for reuse. This process lasts 8 – 12 hours and reduces the caffeine content of raw beans to about 0.08%.
The advantage of using CO2 supercritical fluid is that it is physically between a liquid and a gas, with a viscosity close to that of a gas, so it consumes less energy to transport than a liquid; and its density is close to that of a liquid, so more solvent molecules can be transported per unit of time than a gas. Since almost only the caffeine is dissolved, more odor molecules can be retained in the raw beans, and as soon as it returns to ambient temperature and pressure, the carbon dioxide changes back to the gaseous state and escapes, making it safer than the aforementioned solvents.
There is little else wrong with this method, mainly that it is too costly and not very popular.
Swiss Water Process (Swiss Water)
Another method of removing caffeine from coffee is the Swiss Water process. This process decaffeinates coffee beans with water without the use of organic solvents. The technology was developed in Switzerland in 1933; it was successfully commercialized by Coffex S.A. The Swiss Water Process was subsequently introduced in 1988 by Swiss Water Decaffeinated Coffee Company of Burnaby, British Columbia.
The key to the Swiss Water Decaffeination Method is Green Coffee Extract (GCE Coffee Bean Extract) as the caffeine extraction mechanism.
It can be simply understood as a liquid that retains the coffee flavor substances but removes the caffeine.
By utilizing the water-soluble property of caffeine, the coffee beans are first soaked in warm water, and after the caffeine and other ingredients are dissolved into the water, the caffeine in the extraction liquid is adsorbed by activated carbon, and then the caffeine-free extraction liquid is led back to the previous coffee beans, so as to allow the coffee beans to reabsorb the lost ingredients, and then the beans are dewatered and dried.
This method does not use any organic solvents to extract caffeine, but the disadvantage is that even if the coffee beans are allowed to reabsorb the caffeine-free extract, the flavor of the coffee beans will still be affected.
The more mainstream low-caffeine coffees on the market today are all of this washed method. And most of them are Colombian coffee beans.
Natural Low-Cause Coffee
Among the Bourbon family, there is a special one – “Bourbon with Pointed Body”.
It was discovered in 1810 by Leroy, a coffee farmer from Reunion Island (formerly Bourbon Island). Bourbon Pointu has two other names: Laurina and Leroy, but neither of them is as famous as Bourbon Pointu.
It’s called Bourbon Pointu because of its long, narrow shape and pointed ends, whereas Bourbon Pointu has a shorter body and a slightly oval profile.
The biggest difference is that it is an all-natural decaffeinated coffee. It contains only 0.6% caffeine. However, it has the full flavor of the Arabica species and will have a more rounded taste and fuller flavor than artificially decaffeinated coffee.
Regarding some questions about caffeine content
As mentioned before, the caffeine content is innately determined by the variety. At the extraction stage, there is also a limit to the amount of caffeine that can be extracted from the coffee in a limited period of time. It is certain that the caffeine content of coffee rises only when it is extracted for a long period of time.
In addition, many people say that when they drink dark roasted beans, they will show signs of rapid heartbeat, hyperactivity and palpitations, believing that the caffeine content of dark roasted beans is more than that of light roasted ones. This is definitely wrong, the melting point of caffeine is 235 – 238 ℃, but the temperature at which the coffee beans are roasted is basically around 235 ℃, and basically there is no melting of caffeine. So basically it can be interpreted as a psychological effect on you.
The above value is for reference only, the caffeine content is still mainly based on the time of water and the extraction rate of the change followed. If you want to formulaize, you can simply calculate it according to the following formula:
Calculation method: (caffeine content of coffee beans x amount of ground coffee) x 1000 = how much caffeine a cup of coffee contains (mg).
Assuming that the average caffeine content of Arabica species is 1.3%, the caffeine content can be roughly calculated as follows: (1.3%*10g)*1000 =130mg.
Low-causal coffee products
Although low-cause coffee can be bought in cafes, it is not available in every store and is not cheap, so it is most cost-effective to buy it yourself.
Low-cause coffee products are basically the same as normal coffee products: ear coffee, instant coffee, coffee beans, and coffee capsules.
However, there is a special product called “easy care packets”, which you can think of as capsules for espresso machines.
At present, this kind of “easy care bag” is mainly suitable for 44-45mm handle, so you should pay attention to whether your machine is compatible or not. In addition, in order to better meet the extraction pressure inside the bowl, there will be a special extraction bowl, which you need to change in order to extract correctly.
The general amount of powder for “Easy Pack” is about 7.3g, and it is still recommended to use 1:1.5 – 1.8 for espresso, and if you are making Americano or Milk Café, it is recommended that the ratio of espresso to water (milk) should not be more than 1:8.
If your coffee machine doesn’t fit, but you think this thing is very convenient, you can search for “easy packet coffee maker” on the platform. illy’s machine is the first one to be recommended, and illy itself has produced many kinds of “easy packets” with different roasting degrees, which is also quite convenient.
The benefit of this thing is the same as the coffee capsule, do not have to buy a separate grinder, save a lot of operational steps. Moreover, it has 7.3g of powder compared to 5g of powder in a capsule, so it has an advantage in terms of consistency.
If you are interested in this kind of niche machine, you can buy to try it, but this kind of machine is really not recommended to do milk coffee, if you want to do milk coffee, it is recommended to directly use the microwave oven to heat the milk and pour it on the line.
In Conclusion
Overall, decaffeinated coffee will definitely affect the flavor and taste of coffee to a certain extent. This is a compromise for the sake of caffeine intake, but if you consider caffeine intake, there are many other caffeinated drinks and foods in your life or it’s better to pay attention to them at the same time as well.
Also, decaffeinated coffee is a niche within a niche, and in those days when I owned a store or worked there were very few customers who needed decaffeinated coffee anyway. Therefore, nowadays, very few independent or boutique chains prepare low-causal coffee, and nowadays you can only see it in the traditional large chains. If there is a demand for low-causal coffee, it is better to prepare it yourself.