Composition & Chemistry Flashcards
What are the five major chemical components of wine?
Water, Alcohol, Acid, Sugar, Phenolic compounds
What percent of wine is water?
Typically 80-90%
What is the primary type of alcohol found in wine?
Ethyl alcohol or ethanol
What are two lesser present types of alcohol found in wine?
Glycerol and methyl alcohol
What component of wine gives it its body?
Alcohol
What six types of acid are found in wine?
Tartaric, malic, citric, lactic, acetic, succinic
How are ‘tartrates’ or ‘wine diamonds’ formed?
When tartaric acid reaches low temperatures
What type of acid’s flavor is often associated with green apples?
Malic acid
What are conditions that can lead to a drop in malic acid?
Warm climate, overripe grapes, the ripening phase, malolactic fermentation
What are the two ways of expressing acid content in wine?
Total acid (TA) and pH
Which pH amount is higher in acid content: 3.5 or 2.9
2.9
What are the two types of sugars contained in grapes in approximately equal amounts?
Glucose and fructose
What is the technical term for a simple sugar?
Monosaccharide
What element converts simple sugars into alcohol during fermentation?
Yeast
What are the five types of phanolic compounds present in wine?
Athocyanins, flavonols, vanillin, tannins, reservatrol
Which phenolic compound gives red wine its color?
Athocyanins
Acidity also contributes to a red wines color. More acidic wines appear more ____, while less acidic wines appear more ____
Red, blue
What color pigment are flavonols?
Yellow
What can contribute to an increase in flavonol content?
Sunnier climates
Which phenolic compound acts as a natural preservative?
Tannins
Where do tannins found in wine come from? (List 4 sources)
Grape skins, stems, seeds, and oak
Where do wines get vanillin from?
Oak
Where do a majority of a wine’s phenolic compounds come from? (2 elements)
Skin and seeds of grapes
Is red or white wine more rich in phenolic compounds?
Red
What is the ‘verb’ for when phenolic compounds combine into longer molecule chains
Polymerize
What is the term for polymerized phenolic compounds separated from the liquid of the wine?
Sediment
Aside from the five core elements of wine, list four other components that can be found in wine?
Sulfites, aldehydes, esters, dissolved gasses
Being exposed to heat or being open too long causes wine to become what?
Oxidized
What is the molecule called that is the joining of acid and alcohol?
Ester
What is the most common type of ester?
Ethyl acetate
What is the most prevalent acid found in grapes and wine?
Tartaric acid
What is another term for tartrates?
Wine diamonds
What acid not found in grapes but often produced during secondary fermentation?
Lactic acid
Which acid is both a minor component of grapes and a byproduct of normal alcoholic fermentation?
Succinic acid
What is the typical pH range of most wines?
2.9 to 3.9
Which compound found in wine is known for its health benefits?
Reservatrol
What is meant by polymerization?
When molecules (such as tannins) combine into longer chains
Oxidized alcohols are…
Aldehydes
In the U.S., wines containing more than _____ ppm Sulfur Dioxide must carry a warning label
10
What is the sugar called that remains in a wine post-fermentation?
Residual sugar
