1. Jonathan R. Cave, Andrew Waterhouse, Nick Gislason University of California, Davis Viticulture and Enology

2. Goal Comprehensive model of oxygen availability, necessity, benefit, and detriment from vine to glass Winery Operations Cap Manipulation Racking Crush Pressing Barreling Down Bottling

3. Aerative Pumpovers Splash Racking, Rack and Return, Delestage-ish  High Anticipated Oxygen Solvation  Desired Oxygen Uptake  Early in Fermentation - Low EtOH/High Sugar  SO 2 - Oxygen scavenger and Interaction Inhibitor? Winery Operations Cap Manipulation Racking Crush Pressing Barreling Down Bottling

4.  Yeast Metabolism/Utilization of Oxygen  Oxygen requirements  Lipid synthesis for plasma membrane integrity 1,2  Brewing specification – Strictly monitored/controlled  Yield different aroma and flavor product depending upon available oxygen  Molecular Reactions for Flavor and Aroma  Iron activation to superoxide  Quinone Activation/Fenton reaction  Peroxide radical – highly reactive  Saturation is 8200 ppb 3 Oxygen’s Role in Fermentation

5. Measurement PreSens Oxygen Sensor Spots 4  0.5 cm, Physically Divided (Sight Glass)  Flow Rate Independent  Fiber Optic - Fluorescence Quenching  [O 2 ] = f(Luminescence Decay)  pH, CO 2, H 2 S, SO 2, Ionic Species  Chemical Tolerance – NaOH, H 2 O 2, HCl  CIP - autoclave, steam  Linear Range 0-1800 ppb  Accuracy ± 1 ppb  LOD: 1 ppb  Non-Invasive  Real-time  Non-Destructive  Does not consume oxygen  No Interference/Cross-Sensitivity  Cleanable/Sanitizable  Dissolved Oxygen Range Experimental Requirements

6.  Observed 29 Pumpovers  23 Aerative  6 Closed Controls  Within first 3 days of fermentation  Pumpovers by experienced cellar staff  Well practiced technique  Not harvest interns  No alteration by experimenters  No interference in the production process  Required Observational Treatments Experimental Design

7. Oxygen Sensor Spots– Paired Values

8.  Drop – Distance from Screen to Wine  Splash – Radius and Walls  Flow Rate – From Racking Arm  Flow Type – Screen interaction Parameters Two Conditions  Drop – Large/Small  10” vs. 4”  Splash – Intense/Mild  Spread and Arcing  Flow Rate – Fast/Slow  Flow Type – Turbulent/Laminar

9.  Range: 70 - 2300 ppb  Closed PO Control – 0 ppb  Drop – Most Relevant  STEV of lower [O 2 ] too high  CV > 75% Oxygen Solvation/Assimilation Data Oxygen Assimilation for main observable Treatments SplashFlow RateFlow TypeDrop IntenseMildFastSlowTurbulentLaminarLargeSmall Average (ppb) 1563573110251814739471282205 STDEV 553500874564536717643183 t-Test: Two-Sample Unequal Variances LargeSmall Mean 1282205 Variance 41294833518 Observations 9328 df 119 t Stat 14.3 P(T<=t) one-tail 5.4x10 -28 t Critical one-tail 1.66 P(T<=t) two-tail 1.1x10 -27 t Critical two-tail 1.98

10. Non-Separable Treatments  Coincident Treatments  Interdependence of Rate, Type and Splash  Cannot discern combination of effects or sole influence  Drop is the only separable Parameter  This is not to say they are irrelevant – need more data Data Analysis Treatment Occurrence Turbulent with Large Drop 95% Turbulent with Small Drop 5% Laminar with Large Drop 77% Laminar with Small Drop 23% Total Turbulent 27% Total Laminar 73%

11. Experimental Variation of Large Drop  We should expect no significant difference  Enough variability that operations are unpredictable  Distinct groups within the single treatment  Combination of effects may attribute to variation  Refinement of current technique is necessary Variability Large Drop Treatment ANOVA DfSum SqMean SqF valuePr(>F) Experiment 1429417359210124023.015< 2.2e-16 *** Residuals 76693860991297 Experiment Average (ppb) Statistical Group 27343 a 16416 a 24700 ab 13878 ab 22945 ab 11966 ab 251231 bc 81248 bc 71277 bc 51330 bc 171623 cd 151681 cd 61826 cde 92197 de 232286 e

12.  Variability is immense  Multiple control parameters influence oxygen exposure and solvation  Despite exceptional technique by experienced cellar staff, best control possible, oxygen assimilation into wine by aerative pump over, a commonly employed technique, is inconsistent and capricious.  Technique must be improved  Oxygen levels throughout production are largely uninvestigated  Industry Survey to determine variability  Refinement capability or Operational paradigm shift  Experimentation under strict experimental controls during all winery operations at UC Davis winery  Future collaborations are needed Conclusions and Future Work

13. 1.) Andreasen, A. A., & Stier, T. J. B. 1953. Anaerobic nutrition of Saccharomyces cerevisiae. I. Ergosterol requirement for growth in a defined medium. Journal of Cellular and Comparative Physiology, 41, 23–36 2.) Andreasen, A. A., & Stier, T. J. B. 1954. Anaerobic nutrition of Saccharomyces cerevisiae. II. Unsaturated fatty acid requirement for growth in a defined medium. Journal of Cellular and Comparative Physiology, 43, 71–281 3.) Ough, C.S. and M.A. Amerine. 1988. Methods for analysis of musts and wines, 2nd, Wiley, New York. 4.) Huber, C., T.-A. Nguyen, C. Krause, H. Humele and A. Stangelmayer. 2006. Oxygen ingress measurement into pet bottles using optical-chemical sensor technology. BrewingScience 5-15. References