What makes balsamic vinegar balsamic? Can it be made at home?
Balsamic vinegar, “aceto balsamico’’ in Italian, is in no way easy to make at home.
For starters, it’s not even really vinegar.
Real vinegar comes from the fermentation of alcohol in wine into acetic acid.
Indeed, the word vinegar comes from the Old French “vinaigre,’’ which means “sour wine.’’
Balsamic vinegar, in contrast, is made from the juice of white Trebbiano grapes, the second most widely planted grape worldwide. Juice from Lambrusco grapes or other varieties may be mixed in, too.
The juice, or “mosto,’’ is boiled down, or reduced, to make a thick syrup called “mosto cotto.’’
Then some strong, older balsamic vinegar — “mother of vinegar’’ — is added to ensure that the right microorganisms are present to turn sugar into alcohol and alcohol into acetic acid.
The microorganisms then go to work slowly as the syrup is aged over at least 12 years in a series of successively smaller wooden barrels made of different woods, such as chestnut, acacia, cherry, oak, mulberry, and ash. Juniper wood can been used, as well.
The process requires meticulous care.
The barrels slowly break down but are repeatedly reinforced to keep them intact, because they hold in the valuable microorganisms that do the real work of transformation.
Truly authentic aceto balsamico is made in Modena or Reggio Emilia in Italy.
Imitation balsamic vinegars are made by adding colorings and flavorings to vinegar. They are cheaper and easier to produce in large quantities but a long way from the genuine article in taste.
Balsamic vinegar may have curative properties, but that has not been well researched. It’s a good bet that the polyphenolic compounds present in the grapes are healthy.
But probably the greatest medicinal benefit is the good feeling derived from the pleasure of consuming balsamic vinegar.
Ask Dr. Knowledge is written by Northeastern University physicist John Swain. E-mail questions to firstname.lastname@example.org or write to Dr. Knowledge, c/o The Boston Globe, PO Box 55819, Boston, MA 02205-5819.