Mastering the Grill_ The Owner's Manual for Outdoor Cooking - Andrew Schloss [51]
It would be impossible to detail all the idiosyncrasies of every vegetable in the space we have here, nor is it necessary. To understand vegetables, just look at their interconnections.
Spinach and lettuce might be unrelated, but they’re both leaves and therefore have similar traits. Cauliflower and mushrooms have nothing to do with one another botanically, but they demand the same precautions in cooking because they’re both white. New potatoes share more culinary characteristics with spring peas than they do with mature potatoes, because both are young. The part of the plant from which a vegetable comes, its color, its age, and how it has been stored are what determine a vegetable’s qualities.
01. Roots
Let’s start at the bottom and work our way up the plant. Roots hold the plant in the ground, from which they absorb nutrients and store them as starch and sugar. Like all storage units, roots need strong walls and lots of space. Plant fibers are rigid and contain within their walls large storage chambers (vacuoles). As the plant matures, the vacuoles pack in more sugar and get bigger; at the same time, their walls thicken and get harder. The quality of a root vegetable is therefore a delicate balance between sweetness and toughness. Harvest it too soon and it will be puny and lack flavor; wait too long and its fibers will turn wooden.
This is why the quality of root vegetables is best judged by their size. Small = mild and tender. Medium = crunchy and sweet. Large = tough and tasty. In any bunch of beets or carrots, it’s likely that you’ll get vegetables of different sizes. The larger ones may need to be cooked briefly in liquid to tenderize them before grilling; smaller roots can be grilled directly.
Working our way up, let’s look at tubers, such as white potatoes, water chestnuts, Jerusalem artichokes, and yams. Botanically, these are underground stems, not root vegetables. But because they look like roots, grow like roots, store starch the same way roots do, and are cooked like other roots, culinarily they are considered root vegetables.
02. Stems
Stems do two things. First, they hold up the plant, lifting the leaves toward the sun. Second, they act as a nutrient throughway: Stems contain the veins through which nutrients stored in the root move up to the leaves, fruits, and flowers, and through which sugars manufactured in the leaves descend back down for storage in the roots. To perform these functions, stems are structured a lot like roots. They have rigid support fibers interspersed with hollow veins, but unlike roots, stem fibers are not tough enough to do the job alone. They must be helped by a steady flow of fluid in the veins in order to have the snap (a brief resistance followed by a burst of juice) that indicates quality in a stem vegetable. If the vascular tissue dehydrates, the stem will lose its crispness, and the vegetable will become limp.
In some stem vegetables, like celery or fennel, crispness can be restored by submerging the stalks in ice water. This forces water back into the dehydrated veins. But other stem produce, like asparagus and broccoli, needs to be peeled before it can be revived. These vegetables have a water-resistant skin that delays water loss but also inhibits the ability of the vegetable to regain crispness after it dries out.
03. Fruits and Vegetables
Fruit is the part of a plant that protects and nourishes the seed until it is ready to grow into a new plant. As the seed matures, the fruit ripens, until it is fully colored, loaded with sugar, and bursting with juice, qualities that make it attractive to animals, who hopefully will eat the fruit and scatter the seed, thus helping the plant species to flourish.
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