5. What are the advantages of electricity as a source of heat ?
6. Explain the way in which electricity is measured.
7. Read the gas meter at home and estimate the amount and
cost per day. (The ordinary burner consumes about two cubic
feet per hour.)
8. Obtain the prices of the fuels used in the neighborhood and
work out a comparison of the cost of fuel for preparing a meal.^
9. What are the methods of conserving heat in cooking appari^
tus?
10. Explain the structure and management of a coal stove.
11. Explain the principles involved in making a fire.
12. The structure and management of a gas stove.
13. Why does gas in a burner sometimes " pull back "?
14. State the requirements in a perfect example of cooking ap-
paratus.
^ Teacheb's Note. — If a meter can be used* very exact problems can be
worked out with gas and electricity.
CHAPTER IV
FOOD PREPARATION, THE PRINCIPLES AND
TECHNIQUE
The principles of cooking. — In science the word " prin-
ciple '' ordinarily means a fonnulation of some general or
constant mode of behavior — a generalization based on many
observations of fact. In cookery the word is used in the
same sense ; for example, one may say that an important
principle to bear in mind when cooking with any fat is t>hat
the fats may be melted without decomposition, but when too
strongly heated they begin to decompose with the production
of acrid and irritating products. Sometimes, however, we
speak of " principles of cookery " in a broader and some-
what less exact sense to indicate the general purposes of
cooking operations, as when we say that the most important
principle of vegetable cookery is to soften the fiber without
destroying the flavor or dissolving away the ash constituents
of the vegetable.
That is, the change either chemical or physical that takes
place in a certain foodstuff by the application of heat or
cold or by the use of a fermentation process may be referred
to as the underlying, working principle. We shall study in
detail these changes as we experiment with and prepare each
food material, but a general statement of the effect of heat
on various foodstuffs will be helpful here.
Protein. — There are several forms of protein, with dif-
ferences that we can imderstand only after a thorough study
of chemistry. The most important proteins in meat, fish,
54
FOOD PREPARATION 55
^gs, milk, old beans and peas coagulate, or become slightly
harder or firmer at a temperature below the boiling point of
water. We shall perform an experiment to show this while
studying the egg. There is no marked chemical change;
that is, the protein is not changed to another substance.
Fats, — Solid fats are liquefied by heat, and freed from the
tissue that contains them in animal fats like suet.
When a fat begins to smoke with heat, a chemical change is
taking place. If intense heat is continued, all the hydrogen
and oxygen are driven, ofif and pure carbon remains. When
the fat is " brown," giving the flavor we like, a part of the
oxygen and hydrogen have been driven off. The " boiling "
of fat in a kettle is ordinarily due to the boiling of the water
contained in the fat.
Starch, — Starch occurs in the form of granules. See
Fig. 39. In boiling water, the granule expands and finally
bursts, and frees the content, the pure starch, and the whole
mass thickens.
Page 29
Presented as published in 1914. Historical recipes may not meet modern food-safety standards. Cook from the modern interpretation, not the original instructions.
AI-modernized reading of the original text
5. What are the advantages of electricity as a source of heat ?
6. Explain the way in which electricity is measured.
7. Read the gas meter at home and estimate the amount and cost per day. (The ordinary burner consumes about two cubic feet per hour.)
8. Obtain the prices of the fuels used in the neighborhood and work out a comparison of the cost of fuel for preparing a meal.^
9. What are the methods of conserving heat in cooking apparatus?
10. Explain the structure and management of a coal stove.
11. Explain the principles involved in making a fire.
12. The structure and management of a gas stove.
13. Why does gas in a burner sometimes " pull back "?
14. State the requirements in a perfect example of cooking apparatus.
^ Teacheb's Note. — If a meter can be used, very exact problems can be worked out with gas and electricity.
CHAPTER IV
FOOD PREPARATION, THE PRINCIPLES AND
TECHNIQUE
The principles of cooking. — In science the word " principle '' ordinarily means a formulation of some general or constant mode of behavior — a generalization based on many observations of fact. In cookery the word is used in the same sense ; for example, one may say that an important principle to bear in mind when cooking with any fat is that the fats may be melted without decomposition, but when too strongly heated they begin to decompose with the production of acrid and irritating products. Sometimes, however, we speak of " principles of cookery " in a broader and somewhat less exact sense to indicate the general purposes of cooking operations, as when we say that the most important principle of vegetable cookery is to soften the fiber without destroying the flavor or dissolving away the ash constituents of the vegetable.
That is, the change either chemical or physical that takes place in a certain foodstuff by the application of heat or cold or by the use of a fermentation process may be referred to as the underlying, working principle. We shall study in detail these changes as we experiment with and prepare each food material, but a general statement of the effect of heat on various foodstuffs will be helpful here.
Protein. — There are several forms of protein, with differences that we can understand only after a thorough study of chemistry. The most important proteins in meat, fish,
eggs, milk, old beans and peas coagulate, or become slightly harder or firmer at a temperature below the boiling point of water. We shall perform an experiment to show this while studying the egg. There is no marked chemical change; that is, the protein is not changed to another substance.
Fats, — Solid fats are liquefied by heat, and freed from the tissue that contains them in animal fats like suet.
When a fat begins to smoke with heat, a chemical change is taking place. If intense heat is continued, all the hydrogen and oxygen are driven off and pure carbon remains. When the fat is " brown," giving the flavor we like, a part of the oxygen and hydrogen have been driven off. The " boiling " of fat in a kettle is ordinarily due to the boiling of the water contained in the fat.
Starch, — Starch occurs in the form of granules. See Fig. 39. In boiling water, the granule expands and finally bursts, and frees the content, the pure starch, and the whole mass thickens.