Understanding yeast to prevent hydrogen sulfide (H 2 S) in wine Enlightened science Empowered artistry Matthew Dahabieh, PhD
Volatile sulfur compounds
Viticulture Aging Fermentation Sources of H 2 S
Fermentation
Alcohols x2
Oxidation O 2 Loss of aroma Cu Limited efficacy Loss of flavour
Sulfate S-amino acids Yeast sulfur metabolism
SO 2 SSU1 SO 2 Nitrogen Sulfur metabolism MET3 MET14 MET16 MET10 MET5 (amino acids) MET17 Cysteine STR1 STR4 SO 4 2- SO 3 Homocysteine SUL1,2 MET6 Methionine Wine Yeast
Excess H 2 S (enters wine) Nitrogen (amino acids) MET17 Sulfite MET6 S-containing (SO 3 ) MET10 STR1 amino acids MET5 STR4 *Rate limited Sulfite reductase (MET10)
Evolution s solution Yeast from Lambrusco grape must Emilia Romagna, Italy UCD932 Met10-932 More efficient sulfur usage
Met10 DNA Amino acid Charge H 2 S C Threonine UCD932 A Lysine
No released H 2 S No excess SO 2 Nitrogen (amino acids) MET10-932 MET17 Sulfite MET5 MET6 S-containing (SO 3 ) STR1 amino acids Altered kinetics Increased affinity STR4 *Rate limited Sulfite reductase (MET10-932)
Turning a Clean specialist into a generalist Sparkling Sweet Red Dry UCD932 White Still Aromatic
x Yeast mating: making hybrids
a cell (Haploid) Shmoo formation (Haploid) Cell contact (Haploid) a factor α factor α cell (Haploid) Mating Sporulation Hybrid strain (Diploid) Karyogamy (Diploid) Cell fusion
Haploid Shmoo Cell Hybrid Karyogamy cell pair formation fusion budding
Classical breeding GMO
+ 1st cross UCD932 x + 50% UCD932 50% Strain A
+ 2nd cross x + 25% UCD932 75% Strain A
+ 3rd cross x + 13% UCD932 87% Strain A
+ 4th cross x + 6% UCD932 94% Strain A
+ UCD932 x 50% UCD932 1st cross 50% Strain A + x x + + 25% UCD932 2nd cross 75% Strain A + + + x x Nth cross + x x + 0.5% UCD932 Final cross 99.5% Strain A + +
SO 2 Selection characteristics
H 2 S production BiGGY Lead acetate
SO 2 Selection characteristics
H 2 S-preventing yeast Commercial strain #1 Commercial strain #2 Commercial strain #3 250 Reducing sugars (g/l) 200 150 Fermentation kinetics 100 50 0 0 2 4 6 8 10 12 14 16 Days Chardonnay grape must (YAN 364 mg/l, free SO 2 5 ppm, Brix 21.3)
SO 2 Selection characteristics
Total SO 2 (ppm) 75 SO 2 50 25 SO 2 production 0 Must H 2 S-preventing yeast Commercial strain #1 Chardonnay grape must (YAN 293 mg/l, free SO 2 6.4 ppm, Brix 22.4)
SO 2 Selection characteristics
Gustative harmony Pleasantness Typicality 10 8 6 4 Olfactory intensity Floral 2 Bitterness 0 Apple Sensory H 2 S-preventing yeast Acidity Mature fruits Commercial strain #1 Commercial strain #2 Commercial strain #3 Olfactory balance Bread Honey Prosecco Méthode Champenoise
Enlightened science Empowered artistry Vivace Allegro Andante Maestoso Brioso Ossia ORGANIC H 2 S-Preventing Yeast Developed by Classical Breeding H 2 S-Preventing Yeast Developed by Classical Breeding H 2 S-Preventing Yeast Developed by Classical Breeding H 2 S-Preventing Yeast Developed by Classical Breeding H 2 S-Preventing Yeast Developed by Classical Breeding H 2 S-Preventing Yeast Developed by Classical Breeding 500 g 500 g 500 g 500 g 500 g 500 g Enlightened science Empowered artistry Enlightened science Empowered artistry Enlightened science Empowered artistry Enlightened science Empowered artistry Enlightened science Empowered artistry Enlightened science Empowered artistry
H 2 S-Preventing Yeast Comparison RECOMMENDED VARIETALS SPECIES H 2 S PREVENTION O GMO ORGANIC NON-GMO INOCULATION RATE FERMENTATION TEMPO TEMPERATURE RANGE ALCOHOL TOLERANCE COMPETITIVE FACTOR NITROGEN REQUIREMENTS FOAM PRODUCTION GLUTEN FREE Vivace Chard. Pinot Gris Fruit wine S. cerevisiae bayanus 0.2-0.35 g/l mod-fast 15-30 C (59-86 F) 16% active low-med low RY Vintage 2015 Allegro Andante Sauv. Blanc Chard. Geuwertz. Cab. Sauv. Zinfandel Sangiovese S. cerevisiae bayanus S. cerevisiae 0.2-0.35 g/l 0.2-0.35 g/l moderate moderate 15-28 C (59-82 F) 15-35 C (59-95 F) 16% 17% active neutral medium medium low low RY Vintage 2015 Merlot Maestoso 15-31 C 9 Zinfandel S. cerevisiae 0.2-0.35 g/l moderate 16% neutral high low 10 Cab. Franc (59-88 F) Brioso Pinot Noir S. cerevisiae 0.2-0.35 g/l moderate 15-30 C (59-86 F) 16% neutral medium low Ossia ORGANIC White wine Red wine Fruit wine S. cerevisiae hybrid 0.25-0.4 g/l moderate 16-32 C (61-86 F) 16% active medium low Enlightened science Empowered artistry
Winemaking without worry. Take the Renaissance Challenge. Spicy, smooth, intense Andante RECOMMENDED VARIETALS Cab. Sauvignon Zinfandel Syrah Sangiovese H 2 S-Preventing Yeast Developed by Classical Breeding 500 g GMO H 2 S PREVENTION NON-GMO SPECIES Enlightened science Empowered artistry S. cerevisiae Compare Renaissance Yeast to your favorite wine yeast and see for yourself the quality difference that Renaissance Yeast H 2 S-preventing strains can make for your wine! Enlightened science Empowered artistry