Authentic balsamic vinegar is a splendidly viscous, sweet and sour vinegar that hails from the Emilia-Romagna region of Italy. The towns of Modena and Reggio have been making this stuff for nearly a thousand years, although not for commerce. Families would care for their supply for ages and pass it on as an heirloom, giving it away at times of great importance such as to a daughter as part of her dowry.
Today balsamic vinegar is becoming popular in culinary circles for the special qualities it lends to many dishes.
Balsamic vinegar is produced similarly to wine - aging takes place in a series of wooden barrels over a span of years. The following description is taken from the Balsamic Vinegar Cookbook.
Grapes, picked at the peak of ripeness, are crushed and then pressed into a juice called "mosto". The must is cooked down in open pots over a direct heat and simmered for 24 to 30 hours, so giving an intensely sweet concentrate. During the simmering the grape sugars caramelize slightly, giving an amber color.
This unfermented juice, "mosto cotto", is cooled, allowed to settle, and is traditionally transferred to a "batteria", a set of progressively smaller wooden barrels.
The liquid is stored in attics, "acetaie", usually on the top floor of a house, to ferment, evaporate, and age a minimum of twelve years (and often decades). This yields a complex, aromatic, intensely sweet and syrupy condiment.
A minimum of three barrels are needed for the mosto cotto to undergo "transformazione", "maturazione" and "invecchiamento" (aging). The barrels, 10 to 100 liters in capacity, are of hard and soft woods such as ash, oak, juniper, mulberry, chestnut and cherry. Each barrel lends its flavor and color to the product.
Every stage - from the concentration of the grape juice to the fermentation and oxidation, the incessant evaporation, and the years of storage in varied woods, contributes to the vinegar's layers of sweetness, sourness, earthiness, and intensity.
This traditional process yields very small quantities. 800 gallons of grape must give about 30 gallons of balsamic vinegar. Thus a three-ounce bottle of "aceto balsamico traditionale" can cost one hundred dollars.
Traditional makers from Modena and Reggio have waged a campaign to distinguish their product from cheaper imitations (see below). Today only vinegars which conform to a decree from the Italian Minstry of Agriculture can be labelled "aceto balsamico tradizionale". Vinegars must have been made in the traditional method described above, including a minimum of 12 years aging, produced in the provinces of Modena or Reggio, with no wine vinegar or caramel added. Producers must bring their vinegar before a board of five expert tasters and pass tests for color, density, aroma and taste. Only one-third of vinegars are approved.
Approved vinegars are identified by distinctive bottles and by colored caps: white is a younger vinegar; gold an older one. The consortium of Reggio certifies three levels - "traditionale" "qualita superiore", and the highest, "extra vecchio" - the latter for $175 a bottle.
Certain characteristics exist among all bottles of aceto balsamico traditionale despite aging in different series of barrels, etc... . They are thick, luscious, dark purplish brown, and aromatic, with sweet-and-sour notes in a harmonious blend. The vinegar coats a spoon - it is thick. They taste of everything from old port, toffee, vanilla, carmel and chocolate to plum jam, resinous wood, and herbs as rosemary and thyme.
In the 1970's knowledge and use of balsamic vinegar skyrocketed. To meet the demand producers developed imitations.
To subsidize the large expense of the traditional, artisanal method, many families resorted to experimentation wherein a quality product is made in a shorter time. The resulting vinegars range in price from $16 to $30 per 250 milliliters. I personally have enjoyed this type since I am unable to find the authentic product in San Diego. This artisan-style balsamic vinegar is the most the vast majority of people can afford.
Commercial vinegars, "industriale" in Italy, compose nearly all of the market. They are often packaged in shapely bottles and vary greatly in flavor, quality and price.
Imitation vinegars are not made my traditional methods. They comprise nearly two-thirds of the market. They are usually red wine vinegar cut with water. Without fermentation, they can be made in a day. Cane sugar, caramel, vanilla, and/or herbs are added to fake sweetness and depth.
Fortunately, owing to its intense flavors, a little bit of "tradizionale" goes a long way. It is best drizzled frugally over food just before serving. Cooking with it is not recommended since heat destroys its aromatic qualities.
For culinary purposes an artisan-style balsamic vinegar, or a high-quality "industriale", are better choices.
Here are some simple suggestions that I enjoy:
The following are some ideas for balsamic vinegar, and have been taken from the "Balsamic Vinegar Cookbook". They are more sophisticated than the above and many require advance planning. Exact recipes are available on request.