Ch 11 Wine Components Flashcards
Wine Components
7What are the 8 main components of wine?
- Water
- Acid - tartaric, malic, lactic
- Alcohol (Ethanol)
- Aroma compounds/pre-cursors - from grape, from precursors during ferm, from ferm and by-products, from
other sources - Glycerol
- Residual sugar
- Phenolics
Wine Components
What is main component of wine?
Water = 85% depending on abv, RS and other factors
Wine Components
What is the main alc in wine?
How is it created and what are its characteristics?
What does it contribute to wine?
○ Ethanol - from fermentation
○ Slightly sweet smell
○ Adds fullness to body/mouthfeel
○ Above 14.5%abv -> reduces volatility of wine aromas and adds bitterness; needs fruit concentration to be in
balance
Wine Components
What are the primary acids, where do they come from and what % of acid do they make up?
What are the other non-primary acids and where do they come from?
Primary
* * Tartaric and malic -> come from grape itself
* Make up ~2/3 of acid in warmer climates
Other
* Lactic and acetic -> come from fermentation and MLC
Wine Components
What is volatile acidity and what reaction does it have with other components?
Acetic acid is present at low levels in all wines -> fault when too high
VA comes from acetic acid reacting w/ alcohol -> becomes ethyl acetate
- smells like nail polish remover
Wine Components
What is ethyl acetate?
Reaction of acetic acid w/ alc = VA
Nail polish remover aroma
fault at high levels
Wine Components
What role does acid play in wine?
What happens if too much/too little?
Adds to structure - brings freshness and vibrancy; balances fruit concentration and RS (if any) -> makes wine feel leaner on palate
Too much - too tart
Too little - wine is flabby
Wine Components
What is relationship bet perception of acid and dryness with other components?
Example?
Acid/dryness related to balance of acidity w/other components and to any RS
More acid - tastes drier
Ex - Riesling - tastes dry despite having signif RS (up to 9mg/L) because of high acid
Wine Components
How do levels of individual acids affect tast of wine?
Example?
Tartaric and malic acid most tart, lactic acid softer
Cool climate - more malic = firm acidity which infl its style
E.g., Chard where MLC is blocked
Wine Components
What is relationship between total acidity and pH?
Relationship linked, but not fully correlated
Normally wine w/ higher acidity have lower pH
- other molecules have buffering effect -> potassium
Wine Components
What are 2 main ways of expressing acidity measurement?
- TA in g/L of tartaric acid
- pH level
Wine Components
How is total acidity level measured and expressed - most common and what is normal level?
What is alt measurement?
Most common - TA = sum of all acids -> g/L tartaric
- normal = 5.5 - 8.5 g/L
Alt measure (France) - TA = sulfuric acid -> ratio between sulfuric and tartaric is 1:1.5
Wine Components
What does pH measure, what is its scale, how is it expressed and what is the normal level in wine?
○ pH measures concentration of effective acidity in a solution
○ Normal range for wine - pH of 3-4
○ Inverse scale -> lower means more acid, higher means more alkaline;
○ Logarithmic scale -> pH of 3 is 10x more acidic than pH of 4
Wine Components
What does a lower pH effect in winemaking?
- Promotes microbiological stability
- Increases effectiveness of SO2
- Reds have brighter color
- Enhances age-ability of wines
Wine Components
What are 4 categories of wine aromatic compound types?
- Aromas created from compounds found in grapes
- Aromas created by fermentation due to APCs in grape must
- Aromas from fermentation itself and its by-production
- Aromas from other sources
