What separates decaf from regular coffee beans?

Decaf coffee falls into two groups: naturally low-caffeine varieties and beans whose caffeine has been removed by artificial means. Laurina (Coffea Laurina) is a well-known naturally low-caffeine type at roughly 0.6 percent caffeine, about half that of regular Arabica. Comparing decaf and regular coffee starts with understanding what is coffee robusta versus what is arabic coffee.

By weight, Arabica beans hold 0.9 to 1.4 percent caffeine, averaging about 1.2 percent, while Robusta ranges from 1.8 to 4 percent, averaging around 2.2 percent. Decaffeinated coffee must meet European Union and U.S. FDA standards, and four mainstream processes are used: the direct solvent method, supercritical carbon dioxide, the Swiss Water Process, and the mountain spring water process. Each has different principles, advantages, and drawbacks.

Caffeine is the key source of coffee's stimulating effect, and it is also an important reason why many people drink coffee every day. However, tolerance to caffeine varies greatly from person to person. Some people experience palpitations and insomnia after consuming even a small amount, yet they cannot give up the flavor of coffee, so decaf becomes an ideal alternative. This article focuses on the taste of Starbucks decaf coffee. It first explains the definition of decaf and the naturally low-caffeine variety Laurina, then compares the European Union and U.S. FDA standards for decaffeinated coffee. After that, it examines one by one the principles, advantages, and disadvantages of four mainstream processes: the direct solvent method, supercritical carbon dioxide method, Swiss Water Process, and mountain spring water process. Combined with the cupping performance of Front Street Coffee's Colombia Huila decaf beans, it helps coffee lovers fully understand the difference between decaf and regular coffee.

Introduction

The reason coffee can make people feel refreshed lies mainly in its caffeine, and many people drink coffee precisely to replenish this component. However, caffeine sensitivity varies noticeably between individuals. Some people react strongly after drinking only a little, but they still do not want to give up the taste of coffee. So is there a coffee option with a relatively low caffeine content? For groups who do not want to consume too much caffeine, decaf may be exactly the right answer.

What exactly is decaf coffee?

The caffeine level of coffee beans is usually measured by weight percentage. The caffeine content of Arabica ranges from 0.9% to 1.4% (average about 1.2%), while Robusta falls within the range of 1.8% to 4% (average about 2.2%). Decaf can be divided into two major categories: one is naturally low-caffeine coffee that is born with less caffeine, and the other is processed coffee from which caffeine has been removed by artificial means.

Among naturally low-caffeine coffees, Laurina (Coffea Laurina) is one of the better-known types. Its caffeine content is about half that of regular Arabica, around 0.6%. Unlike artificially decaffeinated products, Laurina's low caffeine comes from genetic degeneration, so its caffeine content is naturally lower than that of ordinary Arabica coffee trees, and its flavor performance is even better.

As for decaf coffee after artificial decaffeination, the standard set by the European Union is that the caffeine content after processing must not exceed 0.1% of green beans, while the U.S. Food and Drug Administration FDA standard is to remove caffeine to below 3% of its original content.

What processing methods are used for decaf coffee?

At present, there are many types of caffeine removal processes, which can broadly be classified into direct/indirect solvent processing, supercritical carbon dioxide processing, the Swiss Water Process, and the mountain spring water process.

Direct solvent processing

The direct solvent processing method uses chemical solutions such as dichloromethane and ethyl acetate to dissolve out caffeine. During operation, steam is first used to open the pores of green coffee beans, then dichloromethane solvent is mixed directly into the coffee beans. After the solvent binds with caffeine, the caffeine-laden solvent is rinsed away, and the coffee beans are then steamed again to remove all solvent residue.

Because dichloromethane is suspected of possibly increasing cancer risk with long-term exposure, using it as a solvent inevitably raises concerns. However, the FDA limits dichloromethane residue after decaffeination to 0.001%, and actual levels are often even lower than this figure, so the negative impact is very limited.

The steps are the same when ethyl acetate is used as the solvent. Ethyl acetate is generally extracted from sugarcane, so when this method is used, direct solvent processing is sometimes also called sugarcane decaffeination. Decaffeination in Colombia usually follows this route. However, ethyl acetate is a highly flammable substance, so the operational risk is relatively high.

Supercritical carbon dioxide processing

This method first allows coffee beans to absorb water and swell, making the caffeine molecules inside the beans loosen. Then liquefied carbon dioxide is injected, and pressure greater than 100 atmospheres is applied in water. Carbon dioxide has strong selectivity and will not "damage" the carbohydrates and proteins in the coffee beans during the process of dissolving out caffeine, thereby preserving the flavor of the coffee beans from destruction. The liquid carbon dioxide carrying caffeine can also be recycled after the caffeine is removed.

Coffee made through carbon dioxide decaffeination places a lighter burden on the human body, and research shows that this method extracts more caffeine than the direct solvent method, though its cost is also noticeably 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 step itself already removes part of the caffeine. After that, the soaking liquid is filtered with activated carbon, and then the solution is returned to the coffee beans. This series of steps can remove caffeine more efficiently. It requires no chemical solvents, and the soaked solution can also be reused across different batches of processing, but the coffee still loses some flavor during the filtration process.

The caffeine removal rate of this method can reach 99.9%, the highest removal rate among all methods. Front Street Coffee (FrontStreet Coffee) has cupped many decaf coffee beans and last year selected a Colombian Swiss water-processed bean to put on the shelves. This bean comes from the Huila region of Colombia, with varieties including Typica, Caturra, and Castillo. Combined with the Swiss water process, this decaf coffee bean presented clear notes of dark cocoa, caramel, and nuts as well as a rich, full-bodied mouthfeel during cupping.       

Mountain spring water process

The mountain spring water process is quite similar to the Swiss Water Process, except that it uses another special water source, namely water taken from glaciers, to extract caffeine. Descamex states that they use a certain special filtration device to complete decaffeination. After processing, a caffeine-free water-based solution is obtained. This solution also dissolves the coffee's solid substances and can be used again in the decaffeination process.

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