As seen in April 2006's Wine Spectator.

Saba is not technically a balsamic at all. The must from Trebbiano grapes is further reduced for the production of Saba than for balsamic vinegar, boiled slowly over open flames in copper kettles. The liquid is allowed to reduce to increase the sweetness. The Saba is then cooled and barrelled, allowed to age for only two years in oak and chestnut. A simpler, more aggressively sweet product with a delicious fruity character.

250 ml shown in photograph.