Oenological Properties of Cryotolerant and Thermotolerant Saccharomyces Strains

Lorena Castellari*, Vincenzo Tini**, Carlo Zambonelli**, Sandra Rainieri**

*Centro di Assistenza Tecnologica in Enologia e Viticultura (C.A.T.E.V.), via Tebano 45, 48018 Faenza (RA), Italy
**Dipartimento di Protezione e Valorizzazione Agroalimentare (DIPROVAL), Universitá di Bologna, Villa Levi, via F. Rosselii 107, 42100 Reggio Emilia, Italy

Article history:
Received September 15, 1997
Accepted November 11, 1998

Key words:
Saccharomyces, cryotolerance, thermotolerance, wine corn position

Summary:
Strains belonging to Saccharomyces sensu stricto are mesophilic yeasts but, in some cases, their temperature performance is peculiar. Some strains, known as cryotolerant, ferment well at low temperatures (6 °C), while other, known as thermotolerant, can ferment at temperatures up to 42 °C. When these two types of Saccharomyces yeasts are used in vinification they produce wines of different composition, especially regarding the fermentation byproducts. Cryotolerant strains produce very low amounts of acetic acid, large amounts of glycerol and succinic acid, and synthétise malic acid rather than degrading it. Thermotolerant strains produce large amounts of glycerol and perform a very intense malo-alcoholic fermentation converting up to 50% of malic acid into ethanol.