They are in greatest perfection when in greatest plenty, i. e. when in full season.
By season, I do not mean those early days, that luxury in the buyers, and avarice in the sellers, force the various vegetables; but that time of the year in which by nature and common culture, and the mere operation of the sun and climate, they are in most plenty and perfection.
Potatoes and pease are seldom worth eating before midsummer; unripe vegetables are as insipid and unwholesome as unripe fruits.
As to the quality of vegetables, the middle size are preferred to the largest or the smallest; they are more tender, juicy, and full of flavour, just before they are quite full-grown. Freshness is their chief value and excellence, and I should as soon think of roasting an animal alive, as of boiling a vegetable after it is dead.
The eye easily discovers if they have been kept too long; they soon lose their beauty in all respects.
Roots, greens, salads, &c. and the various productions of the garden, when first gathered, are plump and firm, and have a fragrant freshness no art can give them again, when they have lost it by long keeping; though it will refresh them a little to put them into cold spring water for some time before they are dressed.
To boil them in soft water will preserve the colour best of such as are green; if you have only hard water, put to it a tea-spoonful of carbonate of potash.[84-*]
Take care to wash and cleanse them thoroughly from dust, dirt, and insects: this requires great attention. Pick off all the outside leaves, trim them nicely, and, if not quite fresh gathered and have become flaccid, it is absolutely necessary to restore their crispness before cooking them, or they will be tough and unpleasant: lay them in a pan of clean water, with a handful of salt in it, for an hour before you dress them.
“Most vegetables being more or less succulent, their full proportion of fluids is necessary for their retaining that state of crispness and plumpness which they have when growing. On being cut or gathered, the exhalation from their surface continues, while, from the open vessels of the cut surface, there is often great exudation or evaporation; and thus their natural moisture is diminished, the tender leaves become flaccid, and the thicker masses or roots lose their plumpness. This is not only less pleasant to the eye, but is a real injury to the nutritious powers of the vegetable; for in this flaccid and shrivelled state its fibres are less easily divided in chewing, and the water which exists in vegetable substances, in the form of their respective natural juices, is directly nutritious. The first care in the preservation of succulent vegetables, therefore, is to prevent them from losing their natural moisture.”—Suppl. to Edin. Encyclop. vol. iv. p. 335.
They should always be boiled in a sauce-pan by themselves, and have plenty of water; if meat is boiled with them in the same pot, they will spoil the look and taste of each other.