Experiment No. 41
Identification of Coffee Berries
Examine Rio, Java, and Mocha coffee berries. Describe each. Note the characteristics of each kind of coffee berry.
Experiment No. 42
Detecting Chicory in Coffee
Fill a beaker with water and place about a teaspoonful of ground coffee on the surface. If much of the ground material sinks and it imparts a dark brown color to the lower portion of the liquid, it is an indication of the presence of chicory. Pure coffee floats on water. Chicory has a higher specific gravity than coffee.
1. How may the presence of chicory in ground coffee be detected? 2. Why does coffee float on the water while chicory sinks? 3. What effect does chicory have upon the color of water?
Experiment No. 43
Testing Hard and Soft Waters
Partially fill a large cylinder with very hard water. This may be prepared by dissolving 0.1 to 0.2 gm. calcium chloride in 500 cc. of ordinary water. Add to this a measured quantity of soap solution. Mix well and notice how many cubic centimeters of soap solution must be used before a permanent lather is formed, also notice the precipitate of "lime soap." Repeat this experiment, using either rain or distilled water, and compare the cubic centimeters of soap solution used with that in former test. Repeat the test, using tap water.