1. Wine Faults 1)Oxidation 2) Microbiological - Candida -…. 3)Sulfur Compounds -mercaptaans - … -… 4) Environmental -Excess sulfur -…… -…...

2. Oxidation Most Common Wine Fault Can Occur Throughout the Process Good effects- soften red wines Generally bad: loss of color bad flavors and aroma

3. Ethanol Acetaldehyde Acetic acid Ethyl acetate 1) Acetaldehyde -ethanol oxidation catalyses by an enzyme (Fermentation) Sensory Threshold o.1 g/l STRAW like flavors or SHERRY Character Off color Brown tints 2) Acetic acid (VA) - Bacteria and oxygen (ML fermentation) Sensory Threshold o.2 g/l ( Table vinegar 50g/l) Table vinegar taste Off color Brown tints 3) Ethyl Acetate (VA) Reaction between ethanol and acetic acid ( unsound grapes) common ester in wines Sensory Threshold o.2 g/l <ST adds sweetness >ST Nail polish or Varnish

4. PREVENTION 1)Use Clean Fruit 2)Chose Low VA Producing Yeast 3)Protect Fermenting Wine 4)Minimize Wine Exposure to Air (Racking) 5)Keep Carboys and Barrels Topped Off 6) Keep Containers Sealed (Tight and clean - stoppers, bungs & waterseals) 7)Maintain Proper SO2 levels SO2 50ppm on unsound fruit 50ppm in first rack 25ppm at each following rack 50 ppm free at bottling (Measure as necessary)

5. Treatmentlow Levels 1) Add 100ppm SO2 2) Potassium Caseinate (Skim milk powder) 3) Blend (very low levels) 4) Referment