1. Nutrient Type and timing for low-pH base wines during yeast acclimatization and tirage in sparkling wine production Jessy Plante, Belinda Kemp, Esther Onguta and Debbie Inglis Cool Climate Oenology and Viticulture Institute, Brock University, St Catharines, Ontario L2S 3A1 (
Introduction
In addition to Chardonnay and Pinot Noir, Riesling base wine is also commonly used for the production of traditional method and Charmat method sparkling wines in Ontario, Canada. The secondary fermentation of sparkling wine requires the acclimatization of yeast to the base wine as the low pH, low nutrient concentrations, high acid, SO2 and high ethanol concentration of the base wine are challenging conditions for the yeast to grow in. No standard recipe exists for micronutrient additions during yeast rehydration or nitrogen additions during the adaptation and proliferation stages of tirage. Some groups recommend using mg N/L (2000 mg/L DAP) additions during yeast adaptation and 68.1 mg N/L (333 mg/L DAP) during yeast proliferation (Valade and Laurent, 2015), while others believe that less is
sufficient. Examples of smaller DAP additions during tirage include additions of mg N/L (666 mg/L DAP) during the adaptation stage (Burrol et al. 2016) or 20 mg N/L (94.3 mg/L DAP) during the adaptation stage and 60 mg N/L (282.8 mg/L DAP) during the proliferation stage (Marti-Raga et al. 2016).
Objectives:
Determine the impact of yeast micronutrient additions during rehydration and nitrogen additions during adaptation (stage 2) and proliferation (stage 3) on yeast viability and sugar consumption during tirage
To investigate ammonia assimilation during stages 2 and 3 of tirage.
Methods
Saccharomyces cerevisiae (EC 1118)
No Go-Ferm® addition
No DAP addition
DAP addition (408.8 mg N/L)
DAP addition (68.1 mg N/L)
Go-Ferm® addition (1.25x mass of yeast)
Stage 1
(0.5 hours)
6 g EC 1118
60 mL 35 oC water
Total Volume: 60 mL
Rehydration
(Stage 1)
60 mL Rehydrated yeast
60 mL Liqueur (500 g/L sucrose in base wine)
60 mL Base wine
Stage 2
(18 hours)
Adaptation
(Stage 2)
Riesling Base Wine
T.A. (g/L tartaric)
7.30±0.01 pH
2.85±0.01
YAN (mg N/L)
26.8±0.4
EtOH (% (v/v))
10.6±0.2
SO2
Free (PPM)
8.4±0.1
Total (PPM)
56.5±0.2
Total Volume: 180 mL
Stage 3
(88 hours)
180 mL Adapted yeast
300 mL Liqueur (500 g/L sucrose in base wine)
300 mL water
1020 mL Base wine
Proliferation
(Stage 3) T1 T2 T3 T4
Total Volume: 1800 mL
Figure 1: Breakdown of treatments by nutrient additions during tirage for 4 replicates
Figure 2: Yeast tirage protocol.
Results
Stage 2
Stage 3
Figure 4: Concentration of viable cells throughout stage 3. The combined treatment had the highest concentration of viable cells while the control had the lowest.
Figure 3: Concentration of viable cells throughout stage 2. All treatments showed similar concentrations of viable cells throughout stage 2.
Stage 2
Stage 3
Figure 5: Rate of sugar consumption throughout stage 2 shown as a decrease in specific gravity over time
Figure 6: Rate of sugar consumption throughout stage 3 shown as a decrease in specific gravity over time and the time required to reach of specific gravity of g/mL
Conclusions and Future Research
Yeast performance was improved during tirage when supplemented with Go-Ferm® during stage 1 and DAP during stages 2 and 3
The quantity of ammonia assimilated by yeast during tirage was 190 ± 50 mg N/L for the DAP treatment and 205 ± 20 mg N/L for the DAP + Go-Ferm® treatment.
DAP and Go-Ferm® have a synergistic effect on yeast performance during tirage but Go-Ferm® does not impact assimilation of ammonia.
The next step will be to determine if supplementing with Go-Ferm® and DAP during tirage improves yeast performance during the secondary fermentation.
References
Figure 7: Ammonia assimilation by yeast during the adaptation and proliferation. Similar nitrogen assimilation was observed for the DAP and DAP + Go-Ferm®.
Burrol, A., Lopez-Martinez, G., Miro-Abella, E., Salvado, Z., Poblet, M., Cordero-Otero, R., Rozes, N. (2016) Food Microbiology 20-29
Marti-Raga, M., Marullo, P., Beltran, G., Mas, A. (2016) Food Microbiology 1-9
Valade, M., and Laurent, M. (2015) Le Vigneron Champenois
Funding provided by OMAFRA – U of G Partnership