Experimental cookery

In pickling, shriveling can be prevented by heating the pickling material slightly and increasing the concentration of the sugar gradually, allowing about 24 hours or more to elapse before the next addition of sugar. But fermentation is more likely to occur when preserves are treated this way. It is a good practise to add the sugar directly to fruits like strawberries and cherries and let them stand over night. The fruit loses water, shrinks somewhat, and becomes slightly tougher. When heated slowly, and if neces- sary removed from the heat for a few minutes before boiling commences, there is time for the sugar to penetrate into the interior of the berry, the fruit is plump and will not float when placed in the container. In the commercially vacuum-processed berries, floating in the can is prevented by adding the berries, to which part of the sugar has previously been added, to a hot sirup, but further heating is not continued until the berries have SOME INVESTIGATIONS ON POTATO QUALITY 133 stood for a few minutes. By producing a vacuum, the greater pressure within the berry tends to puff it up; by breaking the vacuum, flattening occurs. In this way the process of osmosis is helped. Strawberries and the sour cherries develop a strong flavor when boiled for a long time. Hence time must be allowed for the sugar to penetrate into the fruit before the boiling point is reached. Boiling should be rapid, and the quantity of fruit used in a batch small. The popularity of sun preserves for certain fruits is due to osmosis being slow and complete. If the fruit is heated the heating period is very short, so that strong flavors are not developed, less sugar is inverted and caramelized, and the aromatic substances are not lost to such an extent as in long cooking. Since strawberries usually contain about 90 per cent water, it seems a better practise to add the sugar directly to the berries, for not as long a time is required to cook the berries to the concentration desired. When water is added to the sugar to make a sirup it is necessary to evaporate the water used in the sirup as well as a part of that contained in the fruit. Increasing the proportion of sugar to fruit also lessens the time required to reach a definite concentration of the sirup, so that the preserves do not develop as strong a flavor. When 1^ pounds of sugar are used with a pound of strawberries only a short time of cooking is required for the sirup to reach a temperature of 103°C., which gives a sirup containing 60 per cent of sugar. See Table 10. Potatoes What constitutes quality in potatoes? For baking and boiling it is usually accepted that the best potatoes are those that yield a white, com- paratively dry, and mealy texture. The homemaker does not like for boiling a potato that sloughs off badly during cooking, though this often occurs with some of the best baking potatoes. For deep-fat frying, dicing for salad, and other purposes a potato that gives a waxy and firm con- sistency is considered best.