· By Jonathan Parent
Myths and legends:revaluing decaffeinated coffees
In 1905, Ludwig Roselius, a German businessman, invented the first decaffeination process using benzene, now known to be carcinogenic, to remove caffeine from previously moistened beans. Since then, other processes have obviously been developed, the most common of which are decaffeination by water, by a direct solvent and by carbon dioxide. These methods turn out to be gentler and make it possible to preserve some of the organoleptic qualities of coffees, thus contradicting preconceived ideas about decaffeinated products.s.
A 2017 report by the National Coffee Association (NCA) reveals that 42% of decaffeinated coffee consumers are millennials. The latter turn to decaffeinated for health reasons first. While caffeine is not harmful for most people, some still seek to consume it in moderation. However, you should know that decaffeinated coffee is not 100% decaffeinated. Legally, the caffeine content of a decaf must be below 0.1. To achieve this, all the methods developed have this in common that they plan to moisten the green beans, which makes it possible to make the caffeine soluble and extract it using a solvent.
Roasters can either buy pre-decaffeinated beans or send their own batch of coffee to the facilities of their choice. Decaffeinated coffees will taste a little different than their caffeinated counterparts, as the removal of bitter caffeine compounds has an unavoidable effect on flavor, body and acidity. It all depends on the coffee as well as the selected process. The three most common methods are as follows.
Decaffeinated with water
Perceived by many as the most natural and healthy option, this decaffeination process uses water as a solvent to remove the caffeine from the green beans. Since no chemical solvent is used, many consider that this method leaves no residual aroma in the coffee.
Based on the outskirts of Vancouver, Swiss Water has developed such a method to capture only the caffeine and leave the other compounds soluble in the coffee beans. It is thanks to a carbon filter whose pores are adapted to the caffeine molecule that the latter is removed by osmosis. The green beans are immersed in hot water, then introduced into a mixture of water and Green Coffee Extract. In search of balance, the green coffee extract will draw the caffeine from the beans. The mixture is then passed through activated carbon, which traps the caffeine. By multiplying baths and filtering, the green beans are, in the end, almost entirely decaffeinated..
Mexico-based company Descamex has perfected a similar method: the Mountain Water process. He uses the water from the glaciers of the Peak of Orizaba to immerse the green beans in containers. Soluble compounds are added to the mixture which make it possible to maintain certain particles related to flavors inside the green beans and to preserve the taste of the beans at their origin. Everything is then filtered to remove 94%-96% caffeine.
Sugar cane decaffeinated
A substantial portion of Colombia's decaffeinated coffees have gone through this process, as a local Descafecol company is the source. Their process combines a first step during which the green beans are immersed in the solvent, ethyl acetate. This substance is found naturally in certain spoiled fruits and vegetables, including bananas and apples. To produce it commercially, molasses derived from cane sugar is fermented, creating ethanol. Then, this alcohol is mixed with acetic acid to produce ethyl acetate. During the decaffeination process, ethyl acetate attaches to caffeine molecules in order to dissolve them. The green beans are then washed and steamed to remove solvent residues, then are dried until they reach a moisture content similar to that at the start..
This process allows a delicate extraction of the caffeine, without excessive heat or pressure, maintaining the natural structure and characteristics that make the coffee beans unique. Some believe that ethyl acetate has a characteristic odor that can tint coffee once decaffeinated. Others consider cane decaffeinated coffees to have a more pronounced sweetness than plain coffee.
Decaffeinated with CO2
Popular in Europe, CO2 decaffeination involves pushing high pressure (250 to 300 times higher than atmospheric pressure) liquid carbon dioxide into a chamber containing the moistened green beans. Carbon dioxide as used has a density similar to that of a liquid, but its viscosity and diffusivity are similar to that of a gas. The caffeine particles are removed on contact with the CO2, which is then filtered, returns to gaseous state and is recycled. Less common than the other two methods, CO2 decaffeination is more expensive, but offers excellent yields (96% to 98% of the caffeine is removed). With this method, the aromatic compounds are well preserved. Its profile is therefore more similar to that of its caffeinated counterpart.
While decafs have a reputation for being bland and flavorless, the specialty coffee industry shows that you can get great ones. Although decaffeination slightly changes the taste and removes aromatic components from the coffee, some of them retain their natural acidity and sweetness that deserve not to be camouflaged by a too dark roast. You just have to search a little to find them.
Hazel Boydell, What's The Truth About Decaffeinated Coffee, Perfect Daily Grind..
How is Caffeine Removed to Produce Decaffeinated Coffee, Scientific American..
How Is Coffee Decaffeinated, Sprudge..
Step by Step - Crafting Amazing Coffee Without Caffeine, Swiss Water Process.
Tanya Newton, Millennials Turn to Decaf: What Does This Mean for Café Owners, Perfect Daily Grind..