Methoxypyrazines in grapes and wines of Vitis vinifera ev. Carmenere.

Abstract

Vitis vinifera cv. Carmenere, a member of the Cabernet family, was recently rediscovered in Chile where it had been misidentified as Merlot. The Carmenere variety produces complex wines, marked with herbaceous and “green” aromas. Results indicate that methoxypyrazines are present in high concentrations in this variety, probably responsible for the strong vegetative character found in Carmenere wines. Wines from Carmenere grapes had high 3-isobutyl-2-methoxypyrazine (IBMP) concentrations (5.0 to 44.4 ng/L), much higher than most Cabernet Sauvignon wines. The genotype dramatically affected the methoxypyrazine content of Carmenere wines, with some clones containing three-fold more than others. Climatic conditions, rather than maturity or terroir, had a critical effect upon IBMP concentration in grapes. 3-Isopropyl-2-methoxypyrazine evolved differently during grape maturation and was less influenced by harvesting year.