BAKING
Baking naturally comes next to roasting; the two often do duty for one another. As in all other methods of cookery the surrounding air may be many degrees hotter than boiling water, but the food is not appreciably hotter until it has lost water by evaporation, after which it may readily burn. The hot air of the oven is greedy of water, and evaporation is great, so that ordinary baking (i.e., just to shut the food into a hot-air chamber) is not suited for anything that needs moist heat. But baking often means to put some dry substance in a dish with water and to shut it in the air chamber, and under such circumstances it amounts to much the same as boiling with surface heat added.
To test the heat of an oven special thermometers are made. For meat the temperature should be about 300° Fahr.; for bread 360°, afterwards lowered; for pastry about the same, the richest pastry requiring the hottest oven. The heat may be tested with a sheet of writing paper, which curls up brown in a pastry oven, or with flour, which takes every shade from coffee colour to black, when sprinkled on the floor of the oven. Experienced cooks test very accurately with the hand.
The hot air of the oven sometimes imparts disagreeable flavours to the things cooked; but this can be avoided by keeping the oven scrupulously clean and having it well ventilated.
BOILING
Boiling is generally thought to be the easiest method of cooking. Certainly nothing could be less troublesome than the simple process of boiling or stewing meat, and yet beef tough and flavourless, or a leg of mutton boiled to rags is the rule rather than the exception. The success of this culinary method depends entirely upon the liquid in which the material is immersed or partially immersed being kept at a suitable temperature.
The temperature of boiling water at sea-level is 212° Fahr. and 100° Cent. In a mine, where the level is considerably lower than that of the sea, the water reaches a higher temperature before boiling, because the air being more dense offers greater resistance to it; consequently the water must acquire more heat and force to overcome this resistance before it can boil. Conversely, as we ascend a mountain we leave behind the more dense part of the atmosphere, and the column of air, reaching from the earth into space, becomes less in height, and so exerts less pressure on the surface of the water, which consequently boils at a lower temperature. But, whether the water boils gently or is in a state of violent ebullition the temperature remains the same, and anything immersed in the water will cook at an equal rate, although there will be a wide difference between the tender juicy joint
