Note the temperature. Continue to heat the water until bubbling occurs on the surface of the water. Note the temperature. What is indicated by the larger bubbles?
HEATING WATER.--When bubbling occurs below the surface, water is simmering. When the surface is in motion and steam is given off, water is boiling.
[Illustration: FIGURE 19--SCENE ON A TEA PLANTATION.]
The loss of gases makes boiled water taste flat or insipid. This flatness can be overcome somewhat by aerating the water after boiling, i.e. by pouring it from one vessel into another and thus mixing air with it.
TEA AND ITS SELECTION.--Tea shrubs grow in India, Ceylon, China, and Japan (see Figure 19). The buds and leaves of these shrubs are cut and dried and sold as tea.
In buying tea the size of the dried leaves should be noted. The smallest leaves are those which have grown nearest the tip of the twig and hence are the youngest. These make the choicest tea. The older and larger leaves make tea of less fine flavor. "Flowery Pekoe" and "Orange Pekoe" are choice India teas. These brands consist of the buds and youngest leaves.
Another point to consider in buying tea is its color. Tea leaves are either black or green. The chief difference between black and green tea is that black tea leaves are fermented after picking, while green are not. Tea leaves contain flavoring and stimulating materials and a substance called tannin (sometimes called tannic acid) which interferes with digestion. The presence of tannin in both black and green tea can be shown by the following:
EXPERIMENT 9: TANNIN IN TEA.--(a) Put 1/2 teaspoonful of black tea in a cup. Add 1/2 cupful of boiling water. Let it stand for 5 minutes, then strain the infusion.
(b) Repeat (a) substituting green tea for black.
(c) Into 2 test tubes put 1 teaspoonful of each kind of beverage. To each tube, add 1/2 teaspoonful of ferrous sulphate solution and let the tubes stand. If a black substance appears in the tubes, tannin is present. Which kind of beverage,--black or green tea,--shows the greater quantity of tannin?
By fermentation, tannin is changed into a less soluble form, so the beverage made from black tea contains less tannin than that made from green tea. Hence, black tea is preferable. It is, however, slightly more stimulating than green tea. Good black tea is grayish black in color, not dead black. "English Breakfast" is a black tea. It consists of a mixture of several black teas. "Oolong" is black in appearance, but has the flavor of green tea. This is because it is only semi-fermented. Teas grown in various countries have different flavors.
Tea is sometimes adulterated by using the leaves of other plants or by adding large leaves and stems. It is said the finest brands of tea do not reach this country.
MAKING THE BEVERAGE.--Because tea contains tannic acid, an earthen, enamel, china, or silver teapot should be used; a tin teapot should never be used. (See Suggestions for Cooking Fruits.) The ingredient in tea that gives it its odor and flavor is a volatile substance. Hence tea leaves should be kept in closely covered jars or cans.
Boiling water draws out substances which give the beverage its flavor and stimulating properties, while water below the boiling point only partially draws out these substances. If, however, the leaves are boiled or are allowed to remain in water for more than five minutes, much tannin is drawn out in the water. Therefore, never boil tea, but pour boiling water over it and in five minutes strain out the tea leaves.
TEA (proportion for one cupful)
1/4 to 1 teaspoonful black tea leaves 1 cupful freshly boiled water
Heat the teapot by pouring boiling water into it. Pour out the water and add the tea leaves. Pour over them the freshly boiled water. Place the teapot in a warm place to steep, and in 5 minutes strain out the tea leaves.
Teapots provided with perforated cups or with tea-balls (see Figure 20) for holding the tea leaves are most convenient, as the cup containing the leaves may easily be removed or the tea-ball can be drawn above the surface of the liquid after steeping the tea for 5 minutes.