Wine Composition and Chemistry Flashcards
t/f: there are various alcohol types present in wine
True
main alcohol in wine
ethanol
types of alcohol in wine
ethanol (main type)
glycerol
methanol
fusel alcohols aka higher alcohols
What happens when you swirl a glass of wine?
you cause the ethanol in the wine to evaporate; ethanol carries the wine’s aromas to the nose
Acids typically make up __% to __% of a wine’s volume
0.5 - 0.75 %
the prevalent & strongest acid found in wine
tartaric
what is a “wine diamond”
crystallized tartaric acid - tartaric acid crystallizes at low temperatures
this acid is associated with green apples
malic
t/f: citric acid is not a normal component of grapes; it is only found in the winemakers decides to add it
false; naturally found in grape at very, very minuscule levels
is acid is found in most types of vinegar
acetic
high concentrations of this acid is considered a flaw
acetic
this acid is a minor component in grapes + a by-product of fermentation
succinic
grape acids
tartaric
malic
citric (trace amounts)
succinic (minor amounts)
fermentation acids
lactic
acetic
succinic
total acidity vs pH
TA measures the volume of all the acids
pH measures the strength of the acids
typical pH range of wine
2.9-3.9
lower the pH, the ______ the acid
stronger
grapes contain roughly equal amounts of these two sugars
glucose
fructose
t/f: grapes contain tiny amounts of unfermentable sugars
true
this compound is reponsible for color in red wine
anthocyanin
What are phenolics?
various molecules present in wine
yellow pigments found in white wine
flavonols
t/f: more acidic red wines appear bluer in color
false - redder
more acidic wines appear ____ in hue; less acidic wines appear ____
redder / bluer
why do wines from sunnier climates tend to have a more golden color?
flavonols - increases in exposure to sunlight
what are flavonols responsible for?
yellow pigments in wine
why do red wines aged in bottle become less astringent and lighter in color?
over time, tannins and color pigments will polymerize (combine together), eventually becoming too heavy to remain suspended in the liquid and fall as sediment in the wine
what is an aldehyde?
oxidized alcohols - formed when wine is exposed to air
most common aldehyde
acetaldehyde
what is acetaldehyde?
type of aldehyde - formed by the oxidation of ethanol
what are esters?
molecules that result from the joining of an acid + an alcohol
an acid + an alcohol joining together will form…
esters
what are sulfites?
a class of chemicals based on the element sulfur
