Wine Faults

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 ltST adds
  sweetness gtST 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