Wine Composition and Chemistry Flashcards
The most prevalent of the acids found in grapes and wine
Tartaric Acid
The component that makes up 80-90% of volume for most wines
Water
Slow-moving “tears” that can appear in a wine glass after the wine is swirled
Legs
This acid has little to no sensory impact on the majority of quality wines
Citric Acid
The component that makes up 10-15% of the volume of most wines
Ethyl Alcohol
A type of secondary alcohol
Glycerol
Sharp-tasting acid often associated with green apples
Malic Acid
Acid produced via the conversion of malic acid
Lactic Acid
Acid with slightly bitter, slightly salty flavor
Succinic (suck-sin-ick) Acid
Acid found in most types of vinegar
Acetic Acid
What are the six main acids found in wine?
Tartaric Malic Citric Succinic Lactic Acetic
Of the six main acids found in wine, which are typically found in unfermented grapes?
Tartaric
Malic
Citric
Succinic
Of the acids typically found in grapes, which are found in very small quantities?
Citric Acid
Succinic Acid
What are “wine diamonds” made of?
Tartaric Acid - Crystal deposits can form at low temperatures. Not considered a fault.
Winemaking process that changes a wine’s acid components and often provides wines with a creamy texture and buttery aroma
Malolactic Fermentation
Measurement used to define the volume of all acids present in a wine
Total Acidity (TA)
What does pH measure?
Combined chemical strength of all acids present
Typical pH measurement of a highly acidic wine
2.9
Normal range of wine pH is 2.9-3.9
pH measurement you could expect from a low-acid wine
3.9
Normal range of wine pH is 2.9-3.9
Two main fermentable sugars found in wine grapes
Glucose
Fructose
Term used for a wine with no detectable sugar
Dry
Yellow pigments found in white wine
Flavonols
Aromatic compound found in oak barrels
Vanillin
Compound found in wine believed to have health benefits
Resveratrol
One of the most common esters found in wine
Ethyl Acetate
What is an ester?
Molecules that result from the joining of an acid and an alcohol. They form the largest group of odiferous compounds.
The specific component that gives fino Sherries their distinctive aroma
Acetaldehyde
Compounds that give wine it’s red, blue, or purple hue
Anthocyanins
High acid = more red
Low acid = more blue
Bitter compounds found in skin, seeds, and stems of grapes
Tannins
Matter that is sometimes formed as a result of polymerization
Sediment
Tannins and pigments will polymerize (form longer molecule chains) and drop from the wine. As wine ages color lightens (in red wine) and tannins soften/become less astringent
Preservative widely used in winemaking
Sulfur
Oxidized alcohols formed when wine is exposed to air
Aldehydes
Ex: Sherry, Madeira
Promotes the release of wine’s aromatic compounds
Carbon dioxide
Ex: Sparkling wine
True or False
Red wines with high acid will be more blue, low acid will appear more red
False
Anthocyanins work with acid levels -
High Acid = Red
Low Acid = Blue
True or False
White grapes with increased exposure to sunlight will have increased levels of Flavonols
True
Warmer climate (more sun exposure) = more golden color
True or False
Wines exposed to heat can become oxidized
True
True or False
Low concentrations of Ethyl Acetate impart aromas of nail polish remover, while high levels impart aromas of dried rose petals or perfume
False
Low concentrations - fruity & flowery
High concentrations - nail polish remover, glue, varnish
In the United States, any wine containing more than _____ of sulfur dioxide is required to display “Contains Sulfites” on the label
2 parts per million (ppm)
True or False
Normal fermentation does not produce enough carbon dioxide to make a difference in the flavor profile of a typical table wine
False
Carbon dioxide is found even in still wines and keeps a wine feeling fresh. The presence of oxygen in a wine causes oxidation, which can make a wine taste stale or cooked
