Decaffeinated coffee has been produced commercially since the early 1900s, when Coffee Hag was founded in Germany in 1906. Since then, manufacturers have developed a wide variety of techniques, all of which remove a large proportion of the caffeine originally present in the coffee.
Water decaffeination is one of the most respected and common methods in the high-quality decaffeinated coffee industry. This process uses a green coffee concentrate composed of a water saturated with all the soluble coffee components of green coffee minus caffeine. This saturated water will attract the caffeine in the green coffee that we want to decaffeinate.
Descamex is the only Mexican company to decaffeinate coffee with water. It began developing its Mountain Water process in 1980. It has a plant in Cordoba, Mexico, where they also work with the MC process, but here we will focus only on water decaffeination. Belco is particularly interested in measuring and communicating our suppliers’ capacities and the quality of their processes, spotlighting the specific qualities of each method for maintaining most of the sensory characteristics of a green coffee after decaffeination.
On the right side, raw caffeine at the end of the decaffeination process. On the left, semi-refined caffeine
In this process, as with almost all decaffeination methods, facilitating caffeine extraction is essential, which is why, like with the CO2 and Ethyl Acetate processes, coffee is exposed to different stages that will ultimately eliminate 99.9% of the caffeine. As engineer Luis Demetrio Arandia Muguira from Descamex explained, Mountain Water focuses mainly on three main points: preparation, extraction and drying.
In our experience at Belco, water decaffeination processes have characteristics that give the coffee notes of tobacco, malt and caramel, which are all pleasant notes.
A 4-step process
1. Steaming. 5 tonnes of green coffee are exposed to steam. This step is carried out prior to decaffeination and prepares the coffee beans by making them swell and more permeable for the extraction of caffeine.
2. Immersion. Coffee is placed in contact with a saturated solution of soluble solids of green coffee, free of caffeine, at a temperature of 60°C. The vacuum tank raises the pressure in the process. This results in an exchange of components and, according to the principle of osmosis, the caffeine will start to migrate from the coffee to the saturated solution. This solution, once saturated with caffeine, will pass through a carbon and cellulose filter that will collect the caffeine. To guarantee the quality of the process, the coffee is exposed to a continuous flow during 24 hours until achieving the desired level of caffeine.
3. Dryping process. The coffee is exposed to three different kinds of drying for approximately 4 hours: (1) pre-drying in a horizontal dryer designed to quickly eliminate excess water; (2) vertical drying at 60°C, for 2 hours, to bring the coffee to the desired humidity (10-12.5%); (3) cylindrical drying at 25°C in order to lower the temperature of the bean to room temperature.
4. Cleaning. Using a polishing and suction machine, the decaffeinated coffee is cleaned of any membrane residue left from the process and is then ready to be packed.
Water Decaffeination process atMountain Water
Ingineer Daniel Robles Muguira told us an interesting fact about Spain. The country is historically considered the largest consumer of decaffeinated coffee, due to a cultural tradition according to which it is common to offer decaf coffee in the food industry. However, he believes in the accelerated development of “high quality decaf coffee” because the processes already have a solid history, even if historically they were low-quality decaffeinated coffees. Descamex is now taking action to reverse this rumour, since the quality of a decaffeinated coffee depends on the quality of the process, and above all the quality of the green coffee used in the process.
Report: Belco field study of decaffeination processes
Decaffeinated coffees are attracting interest from a new public, more mindful of cup quality, which is something that many decaffeination professionals have clearly understood. At Belco, we place a high priority on integrity, and are firmly commited to supplying quality green coffees. This is why we chose to study the different decaffeination technologies more closely, in order to choose the one that best meets our quality standards. As a result of this research, we are today able to answer many questions and concerns and put paid to some preconceived ideas about “decaf” coffee.
We currently work with four partners, who decaffeinate our coffees using three different processes. César, our quality manager, has travelled the world to find out exactly what each decaffeination process involves. From Canada to Germany, via Colombia and Mexico, click on the links below to read our reports :
Espresso or Filter - Which hides the most caffeine ?
CO2 decaffeination - Behind the doors of the CR3 plant (Germany)
Water decaffeination - Visit of the Mountain Water plant (Mexico)
Sugar cane decaffeination - Visit of the Descafecol plant (Colombia)
Water decaffeination - Interview with Erin Reed, Director of marketing at Swiss Water (Canada)