Project Topic:
Decaffeination of coffee via the Swiss Water method
Chemistry Concept:
Usage of water to decaffeinate coffee and then chloroform to test the level of caffeine in a cup of coffee.
The coffee produced by the swiss water method will have a lower amount of caffeine than the cafeteria cup or the regular cup of coffee.
Journal Articles
Matt's Journal Citation
Swiss water decaf: Science of decaffeination. (n.d.). Retrieved from
Hečimović, I., Belščak-Cvitanović, A., Horžić, D., & Komes, D. (2011). Comparative study of polyphenols and caffeine in different coffee varieties affected by the degree of roasting. Food Chemistry, 129(3), 991-1000. doi: EBSCO Host
Dom's Journal Citation
C. PEHL, A. PFEIFFER, B. WENDL & H. KAESS. (1996). "The effect of decaffeination of coffee on gastro-oesophageal reflux in patients with reflux disease."Department of Gastroenterology, Hospital Bogenhausen, Munich, Germany.
Zosel, Kurt. (1981). "US patent for the process of decaffeination of coffee". US patent office.
Lab Procedure (Source?)
1. Soak beans in hot water
2. pour GCE through carbon filter
3. Introduce new beans to GCE.
4. Repeat step 2
5. Add new beans
6. dry, roast and ground these beans.
7. Make a cup of coffee.
8. Test with chloroform in separatory funnel
Swiss water decaf: Science of decaffeination. (n.d.). Retrieved from
Apparatus & Chemicals Needed
1 buchner flask with vacuum tubes. Un-ground green coffee beans. Regular coffee beans. 1 cup of cafeteria decaf coffee. 3 separatory funnels. Chloroform. 3 300 ml beakers. Filter paper. Charcoal. 2 funnels. 2 250 ml flasks.
Safety Information: Chemicals/Reaction
Chloroform: May be fatal if swallowed, inhaled or absorbed through skin. Causes irritation to the skin, eyes and respiratory tract. may effect the central nervous system, cardiovascular system, liver and or kidneys. Suspected cancer risk Risk of cancer depends on level and duration of exposure. Slightly flamable. Can cause dizziness, drowsiness or death.
Other Information:

Project abstract:
Dominic Dingess, Matt Henneman
This lab was a continuation of an earlier lab carried out by Nicola Volpi and Gabe Brennamen. The decaffeination of coffee using the Swiss water method was the focus. The point of the experiment was to successfully carry out the Swiss water method of decaffeination of coffee, and then compare it to another method of decaffeination, in this case it was the method used by the cafeteria. Green coffee beans were used in the lab. After using the Swiss water process, which produced 200 ml of coffee. 200 ml of cafeteria decaf coffee was procured. A cup of regular coffee was brewed, and yielded 175 ml. Each type of coffee was poured into separation funnels and mixed with chloroform. The chloroform that had been mixed with the cafeteria decaf coffee leaked out overnight, so no data was obtained about its level of caffeine. The total amount of caffeine for our special Cashew’s Cups (TM) cup was 0.089 g. The regular coffee mix yielded only 0.087g of caffeine. When determining final results, the Cashew’s cups mix was extracted in twice the quantity of the regular coffee mix. Had the experiment been carried out with the same amount of coffee in each funnel, the levels of caffeine would have been in our cup’s favor.
Key words: Swiss Water Method, Caffeine, Decaf, differential settling, Separatory funnel.
The Observation Data:
Measurements, if any
Water heated with beans. Water turns green, floating solids could be seen. Smelled like coffee.
Temp of water: 60 C
After heating: 80 C
GCE heated with new batch of beans. GCE turns dark green.
Temp of water:60 C
After heating: 80 C
Charcoal was added to the filter paper. As GCE was poured through, fizzing began. Flow through the paper was slow but steady

GCE is now so green, it’s almost black. New beans are introduced
Temp of GCE: 60 C
After heating: 80 C
200 ml of cafeteria decaf is acquired. Our beans our ground up. Regular caffeinated beans are ground up as well. Our ground up beans are significantly chunkier than the regular bean mix.

2, 250 ml beakers are filled with water. Each was heated. 2 pieces of Filter paper line two separate funnels, which runs out to flasks. Each batch of ground beans was placed in the filter funnel. Water is poured slowly. 175 ml of regular coffee, 200 ml of Cashew’s cups decaf.
Temp of water: 60 C
Temp after heating: 90 C
Each type of coffee has been introduced to separatory funnels and mixed with chloroform. As each funnel is mixed, the chloroform sparkles in the coffee.

The chloroform that was inside of the cafeteria decaf’s funnel leaked out over night. No data can be collected. Chloroform is tapped. The regular coffee chloroform is orange, while the Cashew’s cup mix is light yellow. As the chloroform evaporates from the beakers, density currents become visible.
30 ml of chloroform was tapped from the Cashew’s cup funnel.
20 ml of chloroform was tapped from the regular coffee funnel.
The Results Table

Beaker #1 (Regular coffee)
Beaker #2 (Cafeteria decaf)
Beaker #3 (Swiss method decaf)
Mass of beaker + tape (grams)
Mass of beaker + tape after evaporation (grams)
No result
Mass of caffeine (grams)

Picture of beaker after evaporation