Science in the Kitchen Part 22

VEGETABLES

Vegetables used for culinary purposes comprise roots and tubers, as potatoes, turnips, etc.; shoots and stems, as asparagus and sea-kale; leaves and inflorescence, as spinach and cabbage; immature seeds, grains, and seed receptacles, as green peas, corn, and string-beans; and a few of the fruity products, as the tomato and the squash. Of these the tubers rank the highest in nutritive value.

Vegetables are by no means the most nutritious diet, as water enters largely into their composition; but food to supply perfectly the needs of the vital economy, must contain water and indigestible as well as nutritive elements. Thus they are dietetically of great value, since they furnish a large quant.i.ty of organic fluids. Vegetables are rich in mineral elements, and are also of service in giving bulk to food. An exclusive diet of vegetables, however, would give too great bulk, and at the same time fail to supply the proper amount of food elements. To furnish the requisite amount of nitrogenous material for one day, if potatoes alone were depended upon as food, a person would need to consume about nine pounds; of turnips, sixteen pounds; of parsnips, eighteen pounds; of cabbage, twenty-two pounds. Hence it is wise to use them in combination with other articles of diet--grains, whole-wheat bread, etc.--that supplement the qualities lacking in the vegetables.

TO SELECT VEGETABLES.--All roots and tubers should be plump, free from decay, bruises, and disease, and with fresh, unshriveled skins.

They are good from the time of maturing until they begin to germinate.

Sprouted vegetables are unfit for food. Potato sprouts contain a poison allied to belladonna. All vegetables beginning to decay are unfit for food.

Green vegetables to be wholesome should be freshly gathered, crisp, and juicy; those which have lain long in the market are very questionable food. In Paris, a law forbids a market-man to offer for sale any green vegetable kept more than one day. The use of stale vegetables is known to have been the cause of serious illness.

KEEPING VEGETABLES.--If necessary to keep green vegetables for any length of time, do not put them in water, as that will dissolve and destroy some of their juices; but lay them in a cool, dark place,--on a stone floor is best,--and do not remove their outer leaves until needed.

They should be cooked the day they are gathered, if possible. The best way to freshen those with the stems when withered is to cut off a bit of the stem or stem-end, and set only the cut part in water. The vegetables will then absorb enough water to replace what has been lost by evaporation.

Peas and beans should not be sh.e.l.led until wanted. If, however, they are not used as soon as sh.e.l.led, cover them with pods and put in a cool place.

Winter vegetables can be best kept wholesome by storing in a cool, dry place of even temperature, and where neither warmth, moisture, nor light is present to induce decay or germination. They should be well sorted, the bruised or decayed, rejected, and the rest put into clean bins or boxes; and should be dry and clean when stored. Vegetables soon absorb bad flavors if left near anything odorous or decomposing, and are thus rendered unwholesome. They should be looked over often, and decayed ones removed. Vegetables, to be kept fit for food, should on no account be stored in a cellar with barrels of fermenting pickle brine, soft soap, heaps of decomposing rubbish, and other similar things frequently found in the dark, damp vegetable cellars of modern houses.

PREPARATION AND COOKING.--Most vegetables need thorough was.h.i.+ng before cooking. Roots and tubers should be well cleaned before paring. A vegetable brush or a small whisk broom is especially serviceable for this purpose. If necessary to wash sh.e.l.led beans and peas, it can best be accomplished by putting them in a colander and dipping in and out of large pans of water until clean. Spinach, lettuce, and other leaves may be cleaned the same way.

Vegetables admit of much variety in preparation for the table, and are commonly held to require the least culinary skill of any article of diet. This is a mistake. Though the usual processes employed to make vegetables palatable are simple, yet many cooks, from carelessness or lack of knowledge of their nature and composition, convert some of the most nutritious vegetables into dishes almost worthless as food or almost impossible of digestion. It requires no little care and skill to cook vegetables so that they will neither be underdone nor overdone, and so that they will retain their natural flavors.

A general rule, applicable to all vegetables to be boiled or stewed, is to cook them in as little water as may be without burning. The salts and nutrient juices are largely lost in the water; and if this needs to be drained off, much of the nutriment is apt to be wasted. Many cooks throw away the true richness, while they serve the "husks" only. Condiments and seasonings may cover insipid taste, but they cannot restore lost elements. Vegetables contain so much water in their composition that it is not necessary to add large quant.i.ties for cooking, as in the case of the grains and legumes, which have lost nearly all their moisture in the ripening process. Some vegetables are much better cooked without the addition of water.

Vegetables to be cooked by boiling should be put into boiling water; and since water loses its goodness by boiling, vegetables should be put in as soon as the boiling begins. The process of cooking should be continuous, and in general gentle heat is best. Remember that when water is boiling, the temperature is not increased by violent bubbling. Keep the cooking utensil closely covered. If water is added, let it also be boiling hot.

Vegetables not of uniform size should be so a.s.sorted that those of the same size may be cooked together, or large ones may be divided. Green vegetables retain their color best if cook rapidly. Soda is sometimes added to the water in which the vegetables are cooked, for the purpose of preserving their colors, but this practice is very harmful.

Vegetables should be cooked until they are perfectly tender but not overdone. Many cooks spoil their vegetables by cooking them too long, while quite as many more serve them in an underdone state to preserve their form. Either plan makes them less palatable, and likely to be indigestible.

Steaming or baking is preferable for most vegetables, because their finer flavors are more easily retained, and their food value suffers less diminution. Particularly is this true of tubers.

The time required for cooking depends much upon the age and freshness of the vegetables, as well as the method of cooking employed. Wilted vegetables require a longer time for cooking than fresh ones.

TIME REQUIRED FOR COOKING.--The following is the approximate length of time required for cooking some of the more commonly used vegetables:--

Potatoes, baked, 30 to 45 minutes.

Potatoes, steamed, 20 to 40 minutes.

Potatoes, boiled (in jackets), 20 to 25 minutes after the water is fairly boiling.

Potatoes, pared, about 20 minutes if of medium size; if very large, they will require from 25 to 45 minutes.

Green corn, young, from 15 to 20 minutes.

Peas, 25 to 30 minutes.

Asparagus, 15 to 20 minutes, young; 30 to 50 if old.

Tomatoes, 1 to 2 hours.

String beans and sh.e.l.led beans, 45 to 60 minutes or longer.

Beets, boiled, 1 hour if young; old, 3 to 5 hours.

Beets, baked, 3 to 6 hours. Carrots, 1 to 2 hours.

Parsnips, 45 minutes, young; old, 1 to 2 hours.

Turnips, young, 45 minutes; old, 1-1/2 to 2 hours.

Winter squash, 1 hour. Cabbage, young, 1 hour; old, 2 to 3 hours.

Vegetable oysters, 1 to 2 hours.

Celery, 20 to 30 minutes.

Spinach, 20 to 60 minutes or more.

Cauliflower, 20 to 40 minutes.

Summer squash, 20 to 60 minutes.

If vegetables after being cooked cannot be served at once, dish them up as soon as done, and place the dishes in a _bain marie_ or in pans of hot water, where they will keep of even temperature, but not boil.

Vegetables are never so good after standing, but they spoil less kept in this way than any other. The water in the pans should be of equal depth with the food in the dishes. Stewed vegetables and others prepared with a sauce, may, when cold, be reheated in a similar manner.

[Ill.u.s.tration: Bain Marie.]

If salt is to be used to season, one third of a teaspoonful for each pint of cooked vegetables is an ample quant.i.ty.

THE IRISH POTATO.

DESCRIPTION.--The potato, a plant of the order _Solanaceae_, is supposed to be indigenous to South America. Probably it was introduced into Europe by the Spaniards early in the sixteenth century, but cultivated only as a curiosity. To Sir Walter Raleigh, however, is usually given the credit of its introduction as a food, he having imported it from Virginia to Ireland in 1586, where its valuable nutritive qualities were first appreciated. The potato has so long const.i.tuted the staple article of diet in Ireland, that it has come to be commonly, though incorrectly, known as the Irish potato.

The edible portion of the plant is the tuber, a thick, fleshy ma.s.s or enlarged portion of an underground stem, having upon its surface a number of little buds, or "eyes," each capable of independent growth.

The tuber is made up of little cells filled with starch granules, surrounded and permeated with a watery fluid containing a small percentage of the alb.u.minous or nitrogenous elements. In cooking, heat coagulates the alb.u.men within and between the cells, while the starch granules absorb the watery portion, swell, and distend the cells. The cohesion between these is also destroyed, and they easily separate. When these changes are complete, the potato becomes a loose, farinaceous ma.s.s, or "mealy." When, however, the liquid portion is not wholly absorbed, and the cells are but imperfectly separated, the potato appears waxen, watery, or soggy. In a mealy state the potato is easily digested; but when waxy or water-soaked, it is exceedingly trying to the digestive powers.

It is obvious, then, that the great _desideratum_ in cooking the potato, is to promote the expansion and separation of its cells; in other words, to render it mealy. Young potatoes are always waxy, and consequently less wholesome than ripe ones. Potatoes which have been frozen and allowed to thaw quickly are much sweeter and more watery, because in thawing the starch changes into sugar. Frozen potatoes should be thawed in cold water and cooked at once, or kept frozen until ready for use.

PREPARATION AND COOKING.--Always pare potatoes very thin. Much of the most nutritious part of the tuber lies next its outer covering; so care should be taken to waste as little as possible. Potatoes cooked with the skins on are undoubtedly better than those pared. The chief mineral element contained in the potato is potash, an important const.i.tuent of the blood. Potash salts are freely soluble in water, and when the skin is removed, there is nothing to prevent these salts from escaping into the water in which the potato is boiled. If the potato is cooked in its "jacket," the skin, which does not in general burst open until the potato is nearly done, serves to keep this valuable element largely inside the potato while cooking. For the same reason it is better not to pare potatoes and put them in water to soak over night, as many cooks are in the habit of doing, to have them in readiness for cooking for breakfast.

Potatoes to be pared should be first washed and dried. It is a good plan to wash quite a quant.i.ty at one time, to be used as needed. After paring, drop at once into cold water and rinse them thoroughly. It is a careless habit to allow pared potatoes to fall among the skins, as in this way they become stained, and appear black and discolored after cooking. Scrubbing with a vegetable brush is by far the best means for cleaning potatoes to be cooked with the skins on.