WINE AGEING Flashcards
Why would you age wine? (3)
To soften wine structure
To get maturation flavours
To get stability (color, tartric precipitation, proteins etc)
When does aging begin?
At the moment alcoholic fermentation is stopped
What is another way to describe the process of ‘wine ageing’?
Controlled oxidation process
What are the 3 different types of oxidation?
Chemical
Enzymatic
Microbial
Define chemical oxidation
reaction of polyphenols with oxygen. Converted into quinones and Hydrogen peroxide (H2O2). This oxygen containing compound is a strong oxidising agent which converts ethanol into acetaldehyde
Define enzymatic oxidation
Juice and must is oxidised by an enzyme that is called polyphenol oxidase (PPO) and Laccase in case of botrytis. Phenols are turned into quinones. Easily inhibited by SO2
Define microbial oxidation
Spoilage by Acetic Acid Bacteria (AAB), film yeasts (Candida) and Brettanomyces (Brett). Depending on oxygen.
What is the optimal balance between anthocyanin and tannin?
1/3 or 1/4
The higher the poly phenolic concentration the..
The higher the resistance against oxidation
The higher the polymerisation level, the…
The slower the oxygen consumption
The higher the pH, the..
The faster the oxidation
Which factors are affecting oxygen dissolution in wine? (3)
Temperature
Dissolved CO2
Lees and turbidity
How does temperature influence the amount of dissolved oxygen in wine?
The lower the temp, the higher amount of dissolved O2. Any manipulation or transfer below 10C should be avoided.
What is the ideal temperature for wine manipulation?
Between 15-20C
What dissolves easier in wine, O2 or CO2?
CO2 (around x 100)