Chapter 1: Wine Composition & Chemistry Flashcards
The most prevalent of the acids found in grapes and wine
Tartaric Acid
The component that makes up 80-90% of the volume of most wines
Water
Slow moving “tears” that may appear in a wine glass after the wine is swirled
Legs
Has little or 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
A sharp tasting acid often associated with green apples
Malic Acid
An acid produced via the conversion of malic acid
Lactic Acid
An acid with a slightly bitter, slightly salty flavor
Succinic Acid
The acid found in most types of vinegar
Acetic Acid
Of the 6 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 Acids
What is the name of the wine making process that in addition to changing a wine’s acid components, often provides wines with a creamy texture and a buttery aroma?
Malolactic Fermentation
What measurement is used to define the volume of all the acids present in a wine?
Total Acidity
What does pH measure?
The combined chemical strength of all acids
What is a typical pH measurement of a highly acidic wine?
2.9
What pH measurement would you expect to find in a low-acid wine?
3.9
What are 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
An aromatic compound found in oak barrels
Vanillin
A compound found in wine believed to be beneficial to human health
Resveratrol
One of the most common esters found in wine
Ethyl Acetate
The specific component that gives fino Sherries their distinctive aroma
Acetaldehyde
The compounds that give red wine its red, blue, or purple hue
Anthocyanins
Bitter compounds found in the skins, seeds, and stems of grapes
Tannins
Molecules that result from the joining of an acid and an alcohol
Esters
Matter sometimes formed as a result of polymerization
Sediment
A preservative widely used in winemaking
Sulfur
Oxidized alcohols formed when wine is exposed to air
Aldehydes
Promotes the release of the wine’s aromatic compounds
Carbon Dioxide
Which of the following is the most prevalent type of acid found in both vinifera grapes and wine?
a. acetic acid
b. citric acid
c. tartaric acid
d. malic acid
C. Tartaric acid
Which of the following phenolic compounds is responsible for the bitter taste and drying textural sensation found in many red wines?
a. vanillin
b. tannin
c. athocyanins
d. sulfites
b. tannin
Which of the following is a type of molecule that results from the joining of an acid and an alcohol?
a. aldehydes
b. sulfites
c. flavonols
d. esters
d. esters
What is the typical pH range found in table wines?
a. 2.5 to 3.5
b. 1.9 to 2.7
c. 2.9 to 3.9
d. 3.9 to 4.7
c. 2.9 to 3.9
What is a wine diamond?
a. a small particle created via the crystallization of tartaric acid
b. tannic sediment created via polymerization
c. a by-product of malolactic fermentation that can create a buttery aroma
d. a by-product of the fermentation of fructose
a. a small particle created via the crystallization of tartaric acid
What is methyl alcohol?
a. the primary alcohol component of wine
b. a by-product of polymerization
c. a secondary alcohol produced via fermentation
d. a phenolic compound that provides a citrus fruit flavor in many wines
c. a secondary alcohol produced via fermentation
In the U.S., wine with more that 10 ppm of this compound must have a warning label.
a. dissolved gasses
b. sulfites
c. esters
d. acetic acid
b. sulfites
Which of the following compounds gives red wines their red, blue, or purple hues?
a. anthocyanins
b. tannins
c. aldehydes
d. resveratrol
a. anthocyanins
Which of the following acids, created in small amounts during fermentation, is found in many types of vinegar?
a. succinic acid
b. malic acid
c. citric acid
d. acetic acid
d. acetic acid
Which of the following compounds could cause a wine to have slow thick tears?
a. malic acid
b. flavonols
c. alcohol
d. aldehydes
c. alcohol
True or False. Red wines that are highly acidic tend to appear more blue in color, whereas low acid red wines appear more red.
False
True or False. Tannins can create a textural, drying sensation on the palate.
True
True or False. Madeira is an example of a wine that is produced in such a way that oxidation is encouraged and expected.
True
True or False. Flavonols increase in white grapes with increased exposure to sunlight.
True
True or False. The aromatic compound vanillin, found in vanilla beans, is not found anywhere else in nature.
False
True or False. The phenolic compounds of a grape are concentrated primarily in its skin and seeds.
True
True or False. Wines may become oxidized after being exposed to heat.
True
True or False. It is common for winemakers to encourage the oxidation of white wines such as Chenin Blanc and Riesling by maximizing air exposure during the preliminary stages of fermentation and aging.
False
True or False. Ethyl acetate imparts an aroma similar to nail polish remover or glue at very low concentrations, whereas at higher concentrations it tends to smell of dried rose petals or perfume.
False
True or False. Esters represent the largest group of odiferous compounds found in wine.
True
True or False. Wines with greater than 2 ppm of sulfur dioxide are required to display the “contains sulfites” warning on the label.
False
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
