If you've ever shopped for balsamic vinegar in high-end supermarkets, you'll have noticed that the price of it varies greatly: from less than HK$100 to well over HK$1,000 a bottle. It's not the volume that indicates the price; in fact, the cheaper stuff usually comes in a larger container while expensive balsamic is almost always sold in small bottles.
True denominazione di origine controllata (DOC)-approved balsamic is made in Italy in just two areas - Modena and Reggio Emilia - and the labels on such products will state how old the vinegar is and that it's aceto balsamico tradizionale. It's made primarily from trebbiano, a white grape variety. The grapes are pressed and the juice boiled and fermented before being aged and matured in wood casks using the solera method, which is also used for sherry: as it ages, the vinegar evaporates and the liquid - which becomes increasingly concentrated - is transferred to smaller and smaller containers made from different woods, each of which adds its own flavour. The contents of various barrels are blended and need a combined minimum age of 12 years, although they can be 25 years or older. The blends are tasted and, if approved, they'll receive the DOC recognition. These vinegars are dark, thick and intense, without the mouth-puckering acidity of lesser vinegar; and are the ones sold in small bottles with fancy packaging and at high prices.
Cheaper balsamic doesn't necessarily mean bad balsamic, although it probably won't have the richness or complexity of the aged stuff. Yes, there is some really horrible tasting balsamic out there - it's thin and sour because it's made out of ordinary vinegar mixed with colourings and flavourings. But some of the mid-priced balsamico that's been aged for fewer than 12 years is good, and doesn't have the staggeringly high price tags of the aceto balsamico tradizionale. It's no longer made only in Italy, either - I've tasted good, moderately aged (and moderately priced) balsamic from California, in the United States, and Australia.
Truc (tryk): noun, masculine, trick, gimmick, device. A French word for a chef's secret.