_C._ Test the temperature of the inner part of the double boiler, when the water boils rapidly below. To be exact, a hole should be bored in the cover of the boiler, a cork with a hole inserted, the thermometer run through the cork. An approximate result is obtained by putting in the thermometer, setting on the cover tilted, and covering the opening with a cloth.
_D._ Stir salt into rapidly boiling water in the lower part of the double boiler until no more salt will dissolve (a saturated solution). Test the temperature.
_E._ Put the inner part of the double boiler containing water into this boiling solution of saturated salt, being sure that the inner part is sufficiently deep in the salt solution. Note the temperature of the water in the inner boiler when it becomes heated.
=Boiling at high alt.i.tudes.=--When the air pressure upon the surface of the water is lessened, the water boils at a lower temperature. As the alt.i.tude increases, the air pressure decreases, as many a mountain traveler knows to his cost. The boiling temperature of water is so much lowered that the dwellers in high regions of several thousand feet find it difficult to cook starchy vegetables well. A heavy iron pot is made with clamps for fastening down a tight cover, which increases the temperature somewhat. Experiments _D_ and _E_ indicate a method that can be used to a small extent. The baking process should be largely used, and boiling avoided. For meat, eggs, and fish the lower temperature is not undesirable. (See the chapters relating to these foods.)
=The uses of ice.=--Water freezes and ice melts at the same point, 32 F., or 0 C. If ice is mixed with salt, the temperature is reduced far below the freezing point, nearly to 0 F. This process reduces any watery substance which it surrounds to its freezing point, the heat being used in the melting of the ice. This is an interesting topic to discuss in the Physics cla.s.s.
Ice at its ordinary temperature of 32 F. is used for cooling food agreeably. Its most important function in the refrigerator is as preserver of food for a short time at least. For this it is invaluable, and cheap ice is really necessary in summer to the health of a great city.
=Ice subst.i.tutes.=--Where the supply fails or the price is exorbitant, one property of water makes it a partial aid. The rapid evaporation of water will absorb heat so rapidly as to reduce the temperature of adjacent bodies. In the tropics when ice is lacking, water is hung in porous jars in the breeze, and the temperature of the water in the jar is reduced.
To keep milk and b.u.t.ter cool wrap a wet cloth about the containing jar, and set the jar upon the window sill, keeping one end of the towel in a vessel of water; or the cloth may be wrapped directly around the b.u.t.ter.
This method is surprisingly effective.
=Fruit beverages.=--Fruit juices with water and sugar make refreshing beverages and have nutritive value as well. (See the next chapter.)
=Cocoa and chocolate, coffee, and tea.=--These are the three most important non-alcoholic beverages used by man. They are used because of the agreeable flavor given them by volatile oils, and also because they have a stimulating effect. The stimulating property is due to an alkaloid, a crystallizable substance known in cocoa as theobromine, in coffee as caffeine, and in tea as theine. Chemical investigation indicates that caffeine and theine are the same and theobromine is a closely related substance. These substances have a recognized stimulating effect upon the nervous system, and the beverages containing them should therefore be used with caution by all. In the opinion of the writers, tea and coffee should not be taken by young people under twenty-five years of age. Tea and coffee also contain tannin, an astringent substance giving a disagreeable flavor to coffee and tea when these are improperly made, and having an undesirable effect upon digestion. Chocolate contains a non-volatile fat (cocoa b.u.t.ter) in large amount, and should be cla.s.sed as a food as well as a beverage.
The plants from which cocoa, coffee, and tea are derived are natives of semi-tropical or tropical Africa, Asia, and America, having been introduced to Europe by early travelers in these lands.
The introduction of these beverages is an interesting bit of history. The Spaniards found cocoa in tropical America, and carried it back to Spain, and it was not used in England until 1657. It was sold in Danvers, Ma.s.sachusetts, in 1771, the raw material having been brought by Gloucester fishermen from the West Indies. Coffee is said to have originated in Abyssinia, reaching Europe by way of Arabia, and being sold in England in 1650. Coffee-houses were licensed in America in 1715. A Chinese tradition places the discovery of the use of tea at 2700 B.C. It was first used in England in 1657, and was imported into America in 1711. An amusing story is told of the first tea party in a town of western Connecticut, where the tea was boiled violently in a large iron kettle and served on a platter with the leaves, as a form of soup, the leaves themselves being eaten.
=Cocoa and chocolate.=--Cocoa and chocolate are manufactured from the seed of a tree, _Theobroma cacao_, grown in tropical America. The seeds, when removed from the containing pod, are fermented to improve the flavor, dried, cleaned, roasted, and finally ground. The outer husk is loosened in the roasting, and is then removed, and sold as "cocoa sh.e.l.ls." It is the basis of a cheap beverage with an agreeable flavor. The first crushing of the seeds gives cocoa "nibs," and these are further ground in a mill, and finally molded into the cake of plain chocolate. The addition of sugar, vanilla, cinnamon, and sometimes other spices gives a variety of sweet chocolates. Powdered cocoa is prepared by the removal of the fat, which is a valuable product in itself, sugar and flavorings are added and sometimes a starch. The Dutch manufacturers use alkalies for removing the crude fiber and improving the color, and the consequent loss of flavor is balanced by the use of other flavoring matter. The adulterations of cocoa are largely starch in excess. The French and American cocoas are flavored with vanilla, the Dutch manufacturers using cinnamon as well.
The so-called soluble cocoas are very finely ground, and therefore mix readily with water, remaining in suspension for some time, but the cocoa itself is not dissolved. Powdered cocoa is bought in tin cans, is cheap, and is even more economical if bought in large cans than in small.
Chocolate is more expensive always than the cocoa, and may be bought in cakes in pound packages, or in powdered form for immediate use.
_Coffee_ is the inner seed of a berry from a tree, _Coffea arabica_, the process of manufacture consisting of the removal of the outer pulp, fermentation, washing, drying, and roasting. The first stages of the process are carried on at the coffee plantation, the raw berries being imported, and roasted shortly before using. The roasting in cocoa, coffee, and tea is necessary for desirable flavors, the heat developing volatile, aromatic principles, caramelizing the sugar, and causing other chemical changes. The differences in the flavor of coffees are due to the variety, the soil and climate, and methods of production and manufacture. No coffee grown in the western hemisphere has excelled, and scarcely has any equaled, the original Mocha and Java coffees, and these have long been trade names for coffee from other places, because of the popular liking for these brands. Brazil is now the great coffee producing country of the world, and from South and Central America and the West Indies we obtain coffee of excellent flavor.
The adulterations of coffee should be noted, although these are of the kind that gives the buyer something cheaper in place of coffee, rather than a substance that is injurious. Ground chicory root is sometimes mixed with coffee, but cannot be cla.s.sed strictly as an adulterant, because many people, notably the French, add it openly, preferring its flavor.
Among adulterants are rye meal, bran, beans and peas, cocoa sh.e.l.ls, and even sawdust. Artificial beans have been made of bran, mola.s.ses, and water, sometimes with the addition of chicory and coloring matter. If ground coffee is put into a gla.s.s of cold water, it floats on the top and remains hard, while several of the adulterants named soften and sink to the bottom of the gla.s.s. Highly roasted coffee, however, will sometimes sink. Coffee beans from which coffee extract has been made are sometimes mixed with other coffee.
Coffee extracts and crystallized coffee are manufactured to simplify the coffee-making process, but the flavor is not equal to that of coffee infusion made directly from the bean. A preparation of coffee is also offered with the caffeine removed by some chemical process, but it is expensive in this country.
Buy coffee in the bean, and see that it is freshly roasted. Coffee, whole or ground, is sold extensively by the pound in tin cans, with a fancy label and name, and in this form it is usually expensive. Good coffee may be bought for twenty-five cents a pound of many reliable dealers, and may be purchased in five or ten pound packages, or bought in bulk to be kept in a tightly closed can.
_Tea_ is the dried leaf of a shrub, _Camellia thea_, growing in the comparatively high lands of j.a.pan, China, India, and Ceylon. A tea plantation exists in South Carolina, U.S.A., and furnishes a very pleasing grade of tea, somewhat resembling j.a.pan tea in flavor. We are familiar with the fact that there are many kinds and grades of tea, the tea shrub varying as does the coffee tree, and the methods of curing affecting both color and flavor. The teas from the countries named have characteristic flavors, and each country has different varieties and grades. Russian tea is not grown in Russia, but is Chinese tea carried across the continent of Asia.
In general, tea may be cla.s.sed as green or black, this difference in color depending upon the age of the leaf, and largely upon differences in the curing process. Green tea is made from the young leaf, and after picking is dried immediately by artificial heat, being constantly stirred for about an hour, in which time the leaves twist and curl. For black tea the leaves are allowed to wilt and ferment, before they are rolled and heated; and sometimes the heating is repeated. These details of the process vary in different localities. The leaves are finally sorted and graded for packing.
Both black and green teas are made in China. "Bohea" is one of the famous black Chinese teas. "English Breakfast Tea" is known as such only in America, and is a blend of black teas. Black tea is not so successfully made in j.a.pan as in China. "Oolong," from the island of Formosa, has the appearance of a black tea, with the flavor of a green. In j.a.pan and China old-time methods prevail, with much handling of the tea leaves, but in Ceylon and India modern machinery makes the process a much more cleanly one.
Another cla.s.sification of tea is that depending upon the age and size of the leaf, the young leaf making the finer grade tea. For example, in the black teas of India "flowery pekoe" is made from the youngest leaf, "orange pekoe" from the second, "pekoe" from the third, and "souchong" and "congou" come from the larger leaves.
The adulterations of tea are usually the leaves of other plants, but as a matter of fact very little adulterated tea is imported. The first grades of teas, however, and those most highly prized by the Chinese and j.a.panese, seldom find their way to America.
=Other beverages.=--Several very acceptable coffee subst.i.tutes are on the market, made from roasted and ground grain, and they give an agreeable hot drink for breakfast when served with cream or milk. In some cases they seem to have a laxative effect, which is well for some people and not for others. A pleasant hot drink of the same nature may be made from the browned crusts of bread.
The subst.i.tutes for tea are not usually satisfactory. The Indians of the western coast of the United States make a tea from a plant which they call "Buona Yerba," but for us it has a strong resemblance to the medicinal herb teas formerly used for curative purposes, such as sage, catnip, motherwort, and the like.
GENERAL METHODS AND RECIPES
=1. Lemonade and fruit drinks.=
_Utensils._--Silver knife for paring and slicing, gla.s.s lemon squeezer, a grater, a strainer, and a saucepan. Avoid the use of tin and iron utensils.
_Materials._--Lemon or other fruits, sugar water.
_Proportions._--One half lemon to a gla.s.s, or 2 or 3 to a quart of water.
Other fruits "according to taste." Experiment here, using the juice and pulp of any fruit, combining those that are very acid with those that lack acidity,--lemon and raspberry, for example. One third to 1/2 cup sugar to a quart. The proportion cannot be stated with exactness, for fruit varies in acidity, and the final result must always be tested by the taste.
_Method._
=Plain lemonade.=--After deciding upon the proper amounts to be used, dissolve the sugar in a part of the water, brought to the boiling point.
When cool, add the lemon juice and remaining water, ice and serve. A small portion of grated rind may be added to the boiling water.
Another method is to use lump sugar, rubbing the peel of the lemon upon each lump before dissolving.
The general method is the same with other fruits, pulpy fruit and berries being mashed, the water added, and strained.
_Cherries_, _strawberries_, and pieces of _pulp_ are sometimes added before serving, when the fruit drink is ladled from a bowl as fruit punch.
Be sure to cut the berries if they are large. A brightness is imparted to the fruit punch by the addition of carbonated water just before serving. A quart of fruit punch, if served in small cups, will suffice for eight people.
=2. Cocoa sh.e.l.ls.=
_Principle._--To extract the flavor from the sh.e.l.ls, by boiling in water.
_Utensil._--A saucepan or coffee boiler.
_Proportions._--One half cup sh.e.l.ls to 1 quart boiling water. As much as 1 cup of the sh.e.l.ls may be used.
_Method._
Wash the sh.e.l.ls in a strainer under the faucet. Put the sh.e.l.ls in the pot, pour on boiling water, and simmer gently for 1/2 hour. Strain off, and serve with cream, or milk, or evaporated milk and sugar.
=3. Cocoa.=
_Principle._--To mix the particles smoothly and evenly with the liquid by stirring and by heating.
_Utensils._--A measuring cup, a saucepan, spoon, and beater. A double boiler, if milk only is used.
_Ingredients._--Powdered cocoa, sugar, water, or milk, or milk and water.
Cocoa made with milk does not agree with some people, in which case it may be made with water only, and served with cream, milk, or evaporated milk.
_Proportions._--One teaspoonful of cocoa to 1/2 measuring cup. More or less as preferred. One teaspoonful of sugar, ditto.