Considerations on the use of Torulaspora delbrueckii for winemaking

Torulaspora delbrueckii is probably the most suitable non-Saccharomyces yeast for winemaking. This is because it has a good fermentation performance compared to other non-Saccharomyces yeasts that might be considered for winemaking, such as Hanseniaspora uvarum, H. vineae, Candida zemplinina, C. pulcherrima, C. stellata, Schizosaccharomyces pombe, Hansenula anomala, Metschnikowia pulcherrima, Lachancea thermotolerans, Pichia fermentants, P. kluyveri, and Kazachstania aerobia.

Additionally, it has been claimed that T. delbrueckii can be used to optimize some wine parameters with respect to usual S. cerevisiae wines. However, this option entails additional complications and economic costs in controlling must fermentation with respect to the use of conventional selected strains of S. cerevisiae, which is undoubtedly the most reliable yeast species for this purpose.

Some of the complications of using T. delbrueckii in commercial wineries come from its physiological properties under the stressing conditions that are usual in the winemaking process.

In this work, we review these specific properties, with a focus on their relevance for some applied aspects of winemaking.

Many of the claimed advantages for Torulaspora are based on results from different research studies that are often contradictory, or non-reproducible. The easiest explanation is to attribute these discrepancies to possible differences in behavior of the different strains of T. delbrueckii used in different researches.

However, it is quite possible that the different results found in the literature are due to the variable or unpredictable behavior of T. delbrueckii depending on these environmental conditions.

Given this current situation, in order to obtain the required improvement of wine quality, we would propose for the time being to use single inoculation with T. delbrueckii under appropriate conditions to achieve its full dominance, and then to mix the resulting wines with other S. cerevisiae wines.

Article based on the poster presented at the at the 12th edition of Enoforum (Vicenza, Italy, May 21-23, 2019).