Wine Composition & Chemistry Flashcards
What is the function of glycerol in wine?
Glycerol alcohol is the 3rd most abundant product of fermentation after ethanol and carbon dioxide (typically at 4-10 g/L).
It is sweet tasting, and non-aromatic.
With the exception of botrysized wines (up to 20 g/L), glycerol’s influence on mouthfeel is largely exaggerated.
What acid is produced via the conversion of malic acid
Lactic acid
What does succinic acid taste like?
Slightly salty, slightly bitter.
Can appear in a wine glass when there are high levels of alcohol or sugar
Legs or
Which acid is found only in small amounts in wine, and has little sensory impact?
Citric acid
The acid found in most types of vinegar
Acetic acid
The byproduct of fermentation that makes up 10-15% of the volume of most wines
Ethanol (ethyl alcohol
The compound that makes up 80-90% of the volume of most wines
Water
The most prevalent of the acids found in grapes and wine
Tartaric acid
A sharp-tasting acid often associated with green apples
Malic acid
Of the six main acids found in wine, list those that are typically found in unfermented grapes.
Tartaric Acid, Malic Acid, Citric Acid, and Succinic Acid
Of the acids typically found in grapes, which are found in very small quantities?
Citric Acid and Succinic Acid
Which acid is known to cause deposits known as wine diamonds?
Tartaric Acid
What is the name of the winemaking process that, in addition to changing a wine’s acid components, often provides wines with a creamy texture and buttery aroma?
Malolactic fermentation
What measurement is used to define the volume of all acids present in a wine?
TA - Total acidity
What does pH measure?
The combined chemical strength of all acids present
What is a typical pH measurement of a highly acidic wine?
2.9 (considering the normal range of wine pH ranges from 2.9 - 3.9)
What pH measurement would you expect to find in a low-acid wine?
3.9 (considering the normal range of wine pH ranges from 2.9 - 3.9)
What are the two main fermentable sugars found in wine grapes?
Glucose and Fructose
What term is used to describe a wine that does not contain any detectable sugar?
Dry
Yellow pigments found in white wine
Flavonols