Issue link: http://winesandvines.uberflip.com/i/331901
56 p r a c t i c a l w i n e r y & v i n e ya r d J U ly 2 0 1 4 W I N E M A K I N G U.S.A. MAIN OFFICE - 1460 Cader Lane, Suite C - Petaluma, CA 94954 - Phone: (707) 775-4530 - laffortusa@laffort.com St HELENA STORE - 1309 Main Street, Suite C - St Helena, CA 94574 - Phone: (707) 967-8290 A new yeast for complex, barrel fermented Chardonnay, with notes of almond, hazelnut, toasted bread and lemon. From the best terroir of Burgundy ZYMAFLORE® CH9 New for 2014 ugation, enzyme treatments and cold set- tling) can reduce the initial population of yeasts. In red must, wild yeasts are usually encouraged by cold soaking. In general, wild fermentation benefits from being ini- tially protected from air, but once the fer- ment is active, aeration is advantageous for yeast activity. Similarly to inoculated fermentation, wild fermented musts con- taining low yeast assimilable nitrogen (YAN) will deliver wines with more com- plex "mineral" and "funky" styles, while nitrogen addition will produce wines with a cleaner and more fruity style. The range of flavor compounds pro- duced by different non-Saccharomyces yeasts includes terpenoids, esters, higher alcohols, glycerol, acetaldehyde, acetic acid and succinic acid. Although far less studied, wine color can also be affected by non-Saccharomyces yeast. Various research articles have reported on deliberate inoculation of selected non-Saccharomyces yeasts for wine production. These included Torulaspora delbrueckii, Metschnikowia pulcherrima (Candida pulcherrima), Candida zemplinina (Candida stellata), Hanseniaspora species, Zygosaccharomyces species, Schizosaccha- romyces species, Lachancea thermotolerans (formerly Kluyveromyces thermotolerans), Pichia species, Hansenula anomala, Willi- opsis saturnus, Candida cantarellii, Issatch- enkia orientalis and Saccharomycodes ludwigii. Combinations of more than one species of non-Saccharomyces yeasts have also been investigated. Most of these yeasts are poor fermenters, therefore S. cerevisiae (either indigenous or inoculated) is always needed to complete wine fermen- tation. Typically, non-Saccharomyces yeasts have been used in sequential fermenta- tion where these yeasts are allowed to grow or ferment between one hour and 15 days before inoculation with S. cerevisiae. Wines fermented with non-Saccharomy- ces yeast have shown different chemical composition and/or different flavor and aroma when compared to wines fer- mented only with S. cerevisiae. Although many of these trials were conducted on a laboratory scale utilizing small volumes of grape juice, and the results may not be the same as what could be expected in larger commercial fermentations, they demonstrate the potential of non-Saccharomyces yeast to produce distinctive wines. As a result, a few non-Saccharomyces yeasts have already been commercialized. Conclusions The diverse array of yeast available to a winemaker through the cellar environ- ment, in the air, on the grape or through inoculation remains a crucial element to wine production with a wide range of com- plex flavors and aromas. Harnessing the performance of fermentation for a desired outcome tantalizes and challenges. Research undertaken in S. cerevisiae can make great contributions to understanding the role and uses of non-Saccharomyces yeast in spontaneous and "inoculated multi-species" ferments. The management of "mixed-ferments" is more complex than "single-species" ferments because so many things can go wrong. Therefore, a modern approach to "multi- species" wine ferments backed by frontier science and rigorous research is essential to help winemakers achieve their primary objective of a better than 98% conversion of grape sugar to alcohol and carbon diox- ide at a controlled rate and without the development of off-flavors. Therein lies wine's magic blend of art and science. PWV This article is a summary of findings reported in: N. Jolly et al. "Not Your Ordinary Yeast: non-Saccharomyces Yeasts in Wine Production Uncovered," FEMS Yeast Research (2014) 14: 215–237.