The most useful thing one can know about basil is that the less it cooks, the better it is, and that its fragrance is never more seductive than when it is raw. It follows, then, that you will add basil to a pasta sauce only after it is done, when it is being tossed with the pasta. By the same consideration, that most concentrated of basil sauces, pesto, should always be used raw, at room temperature, never warmed up. Occasionally, one cooks basil in a soup or stew or other preparation, sacrificing some of the liveliness of its unfettered aroma in order to bond it to that of the other ingredients. If you are in doubt, however, or improvising, put it in at the very last moment, just before serving.
Balsamic vinegar, a centuries-old specialty produced in the province of Modena, just north of Bologna, is made entirely from the boileddown the concentrated, sweet juice of white grapes. True balsamic vinegar is aged for decades in a succession of barrels, each made of a different wood.
How to judge it?
The color must be a deep, rich brown, with brilliant flashes of light. When you swirl the vinegar in a wine glass, it must coat the inside of the glass as would a dense, but flowing syrup, neither splotchy nor too thin. Its aroma should be intense, pleasantly penetrating. A sip of it will deliver balanced sweet and sour sensations, neither cloying nor too sharp, on a substantial and velvety body. It is never inexpensive, and it is too precious and rare ever to be put up in a container much larger than a perfume bottle. The label must carry, in full, the officially established appellation, which reads: Aceto Balsamico Tradizionale di Modena.