Decaffeination
Process removing caffeine from coffee and tea.
Wikipedia / Wikimedia Commons
Decaffeination is the process of removing caffeine from materials like coffee beans, cocoa, and tea leaves. Products that have undergone this process are often called decaf. To maintain quality, manufacturers must test decaffeinated coffee beans to confirm their caffeine levels are low. Under U.S. FDA rules, the caffeine content must be reduced by at least 97%. A 2006 study showed that decaffeinated drinks usually contain 1–2% of their original caffeine, though occasionally as much as 20%.
The first isolation of caffeine from coffee beans was carried out by Friedlieb Ferdinand Runge in 1820, after the poet Goethe, aware of Runge’s work on belladonna extract, asked him to analyze coffee beans. Runge isolated the compound but did not explore its chemistry further or develop a commercial decaffeination process.
Several methods exist for decaffeinating coffee, all applied before roasting. These methods may use organic solvents like dichloromethane or ethyl acetate, supercritical CO₂, or water to extract caffeine while preserving flavor precursors as much as possible.
The first commercially successful decaffeination process was invented by German merchant Ludwig Roselius and his colleagues in 1903, after Roselius noticed that coffee beans accidentally soaked in seawater had lost most of their caffeine but retained flavor. Patented in 1906, the process involved steaming beans with acids or bases, then using benzene to remove caffeine. Coffee made this way was sold as Kaffee HAG in much of Europe, Café Sanka in France, and later Sanka in the United States. These are now Kraft Foods brands. Similar methods, known as the direct organic solvent method, remain common. Due to benzene’s carcinogenicity, solvents like dichloromethane or ethyl acetate are now used. Green beans are steamed and rinsed with solvent 8 to 12 times until caffeine meets standards—97% removal under U.S. rules or 99.9% under EU rules.
An indirect organic solvent method also exists. Beans are soaked in hot water for several hours, then removed. The water is treated with solvents to extract caffeine, which is separated by evaporation. The water is reused with new bean batches until an equilibrium is reached, where only caffeine is removed, preserving flavor. This method, first mentioned in 1941, is sometimes called “water-processed.” Efforts have been made to avoid organic solvents entirely.
The Swiss Water process, developed in Switzerland in 1933 and commercialized by Coffex S.A. in 1980, uses no organic solvents. It was introduced by The Swiss Water Decaffeinated Coffee Company of Burnaby, British Columbia, in 1988. This method uses green coffee extract (GCE), a solution of water-soluble green coffee components minus caffeine, made by soaking beans in hot water and filtering through activated charcoal. Fresh beans are added to the caffeine-lean GCE; caffeine migrates from the beans into the GCE due to concentration differences, while other components stay in the beans. The caffeine-rich GCE is then filtered again to remove caffeine, and the batch process repeats over 8–10 hours. Food engineer Torunn Atteraas Garin also developed a decaffeination process.
In the triglyceride method, green beans are soaked in hot water and coffee solution to bring caffeine to the surface. They are then transferred to another container and soaked in coffee oils from spent grounds. After several hours at high temperature, triglycerides in the oils remove the caffeine without affecting flavor.
- first_caffeine_isolation
- 1820 by Friedlieb Ferdinand Runge
- first_commercial_decaf_process
- 1903 by Ludwig Roselius
- US_standard
- 97% caffeine removal
- EU_standard
- 99.9% caffeine-free by mass
- common_solvents
- dichloromethane, ethyl acetate, supercritical CO2, water
- Swiss_Water_process_origin
- Switzerland, 1933
Lore & Background
Friedlieb Ferdinand Runge performed the first isolation of caffeine from coffee beans in 1820, after the German poet Goethe heard about his work on belladonna extract, and requested he perform an analysis on coffee beans. Though Runge was able to isolate the compound, he did not learn much about the chemistry of caffeine itself, nor did he seek to use the process commercially to produce decaffeinated coffee. The first commercially successful decaffeination process was invented by German merchant Ludwig Roselius and co-workers in 1903, after Roselius observed that a consignment of coffee beans accidentally soaked in sea water had lost most of their caffeine content while losing little of their flavour. The process was patented in 1906, and involved steaming coffee beans with various acids or bases, then using benzene as a solvent to remove the caffeine. Coffee decaffeinated this way was sold as Kaffee HAG in most of Europe, as Café Sanka in France and later as Sanka brand coffee in the United States.
Reader's Guide
Decaffeination processes have evolved from the use of benzene, now recognized as a carcinogen, to safer solvents such as dichloromethane or ethyl acetate, as well as methods using only water or supercritical CO2. The Swiss Water process, developed in Switzerland in 1933 and commercialized in 1980, uses no organic solvents, relying instead on green coffee extract and activated charcoal filters. The supercritical CO2 method, developed by Kurt Zosel, uses carbon dioxide at high pressure and temperature to extract caffeine while leaving flavor compounds largely intact. These methods allow consumers to enjoy coffee with greatly reduced caffeine content, though studies show that decaffeinated drinks can still contain 1–2% of original caffeine, and sometimes as much as 20%. The industry continues to refine techniques to meet regulatory standards and consumer demand for natural processes.
Did You Know?
- A 2006 study found decaffeinated drinks to contain typically 1–2% of the original caffeine content, but sometimes as much as 20%.
- The first commercially successful decaffeination process was invented by German merchant Ludwig Roselius in 1903 after a consignment of coffee beans accidentally soaked in sea water.
- The Swiss Water process, first developed in Switzerland in 1933, uses no organic solvents and relies on green coffee extract and activated charcoal filters.
- Supercritical CO2 decaffeination was developed by Kurt Zosel of the Max Planck Institute.
Frequently Asked Questions
Who is Decaffeination?
Decaffeination is the process of stripping caffeine out of coffee beans, tea leaves, cocoa, and other caffeine-bearing ingredients. The resulting products are widely known by the shorthand 'decaf.'
What are Decaffeination's powers/role?
Its core function is to reduce the caffeine content in a product to a very low level. Under U.S. FDA rules, at least 97% of the original caffeine must be removed before the product can be sold as decaffeinated.
Where did Decaffeination come from?
Caffeine was first isolated in 1820 by chemist Friedlieb Ferdinand Runge, but the first commercial decaffeination method was not developed until 1903 by Ludwig Roselius. The solvent-free Swiss Water process traces its origins to Switzerland in 1933.
Why is Decaffeination important?
It lets people who are sensitive to caffeine or simply want to avoid it still enjoy coffee, tea, and cocoa. Manufacturers must test finished beans to verify the caffeine level is sufficiently low, and the EU goes even further by requiring 99.9% caffeine-free by mass.
What tools does Decaffeination use?
Common solvents in the process include dichloromethane, ethyl acetate, supercritical carbon dioxide, and plain water. The chosen method affects both the residual caffeine level and the flavor profile of the final product.
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