1. Chenin blanc seminar 19 August 2009 THE INFLUENCE OF YEAST ON CHENIN BLANC AROMA KARIEN O’KENNEDY

2. Chenin blanc seminar 19 August 2009 Wine aroma Pyrazines Thiols Monoterpenes and C 13 - Norisoprenoid derivatives Esters Phenolic compounds

3. Chenin blanc seminar 19 August 2009 Chenin blanc Thiols Esters Monoterpenes? C 13 – Norisoprenoid derivatives?

4. Chenin blanc seminar 19 August 2009

5. Chenin blanc seminar 19 August 2009 Volatile thiols

6. Chenin blanc seminar 19 August 2009 Stability of volatile thiols University of Auckland – presented at the 13 th AWITC in Adelaide 2007 16 Marlborough S. blancs – 3MH and 3MHA 0, 3, 7 and 12 months Cork and screw cap 3MHA was very unstable and disappeared after one year 3MH declined more slowly and in some wines increased Type of closure did not have a significant impact

7. Chenin blanc seminar 19 August 2009

8. Chenin blanc seminar 19 August 2009 Monoterpenes + C 13 - Norisopreniod derivatives Increase with ripening Free and bound forms in grape juice Tropical fruit, apple, floral Yeasts with ß-Glucosidase activity

9. Chenin blanc seminar 19 August 2009 Survey 16 winemakers 21 wines Style, price, vineyard, °B, RS, yeasts, nutrients, tannin, MLF, Wood

10. Chenin blanc seminar 19 August 2009 Fresh and fruity VIN 7, CKS 102, Alchemy II, QA 23, NT 116, VIN 13 20.5 – 23.5°B 11 – 15°C March – August R25 – R43 Volume pushers – 800 000L

11. Chenin blanc seminar 19 August 2009 Full ripe without wood Alchemy I, VL 3, VIN 7, VIN 13/NT 116, VIN 7/QA 23, VIN 2000 23.5 – 25.6°B 11 – 16°C May, August, Sept., Oct, – next year R30 – R65 225 000 L biggest volume produced (6000 – 30 000L)

12. Chenin blanc seminar 19 August 2009 Full ripe with wood Natural, CY 3079, D 47, D254, L2056, VIN 2000, VIN 13 Tank: Cross Evolution, VIN 13, QA 23, VIN 7/QA23, Alchemy II 13°C – 20°C Sept., next year, 2 years after 1200 L – 5600 L (90 000L)

13. Chenin blanc seminar 19 August 2009 Non- Saccharomyces yeasts University of Auckland Candida spp. and Pichia spp. 90% NS and 10% Saccharomyces S. blanc, 3MH and 3MHA Significant increase in [3MHA] as well as a significant decrease in [3MH]. Nietvoorbij Candida research

14. Chenin blanc seminar 19 August 2009 Non-Saccharomyces - aroma contribution Chenin blanc: C. pulcherrima / S. cerevisiae 2000 to 2006 Yeast combinationRelative score 2000200120022003200420052006 5m5m 18 m 5m5m 18 m 5m5m 5m5m 5m5m 5m5m 5m5m 5m5m 3m3m Reference-2-2 1-2-303 825 & VIN 132510-2––2–– C1-15 & VIN 13––431123-2-31

15. Chenin blanc seminar 19 August 2009 Anchor Yeast Chenin blanc challenge Fresh and fruity: Perdeberg Rich and Ripe: Simonsig Rich and Ripe with wood: Mulderbosch Small Change