Wine Chemistry & Faults Flashcards
List the 5 major components of wine.
Water, alcohol, sugar, acid, phenolic compounds
Other compounds that are found in wine what have been aged or sur lie (found in very small amounts) are
Yeast and proteins
Water makes up _____% volume of wine.
80%-90%
Alcohol makes up ____% volume of wine.
10 - 15%
What is the primary alcohol found in wine?
Ethyl alcohol
What 3 other types of alcohol are found in wine?
Glycerol, methanol and fusel
Acid give wine much of it’s
Structure, balance & thirst quenching qualities
Acids make up ____% volume of wine
.5 -.75%
What are the 6 principal acids found in wine?
Tartaric, malic, citric, lactic, succinic, acetic
What is the most prevalent acid found in wine?
Tartaric
What acid is the strongest in terms of pH?
Tartaric
The sharp tasting acid frequently associated with green apples is
Malic
Under ripe and cool climate grapes are typically high in ____ acid.
Malic
Which acid exists in such minute amounts that special equipment is required to measure it?
Citric
Lactic acid is created in wine by lactic acid bacteria. T or F
True
The acid found in most types of vinegar is
Acetic
Acetic acid is volatile. T or F
True
Acetobactor is the result of a chemical reaction between oxygen &
Ethanol
What acid has a sharply bitter and salty taste?
Succinic
What are the grape acids?
Tartaric,
malic
citric
Succcinic (in ___and in fermentation)
What are the grape fermentation acids?
Lactic,
acetic
succinic (in both grapes and in ___)
Total Acidity (TA) refers to
the volume of all acids in the wine.
The pH level of a wine represents
the combined chemical strength of the acids present.
The combined chemical strength of the acids present in wine is measured by
The pH level
The volume of all acids present in wine is measured by
The Total Acidity (TA)
Grapes contain ___% to ___% of sugar at harvest
15% - 28%
Grapes contain roughly equal amounts of what two sugars?
Fructose and glucose
List the 5 phenolic coumpounts found in wine?
Anthocyanins, flavanols, vanillin, tannin, resveratrol
Which phen compound gives red wine it’s color?
anthocyanins
Which phen compound gives white wine it’s color?
Flavanol
The phen compound that gives big red wines “backbone” is
Tannin
Which phen compound is a natural preservative?
Tannin
Which aromatic phen compound is found in oak?
Vanillin
The phenolics of a grape are concentrated primarlily in its _____ and ______.
Skin and seeds
When some phen compounds combine into longer molecule chains it’s called
Polymerization
List 4 other minor compounds of wine.
Aldehydes, esters, sulfites, dissolved gasses.
Oxidized alchohols that are formed when wine is exposed to air are called
Aldehydes
The most common aldehyde found in wine is
acetaldehyde
Esters are molecules that result in the joining of a _____ and _______.
Acid & alcohol
The most common ester found in wine is
ethyl acetate
Ethyl acetate is the ester of _______ and ______.
Ethanol and acetic acid
imparts a fruity, flowers aroma
In high concentrations ethyl acetate imparts faulty aromas of
nail polish remover, varnish, glue
What dissolved gas is routinely found in wine?
Carbon dioxide
“Contains Sulfites” must be on US labels that contain more than ______ of sulfur dioxide.
10ppm
Wines with a musty, moldy, dank basement, wet cardboard aroma are often found to have what fault.
2,4,6 TCA or cork taint
Another term for TCA is
cork taint
TCA is a mold. T or F
True
Most people can detect TCA at concentrations of ____ to ____ parts per ______.
2 to 7 parts per trillion
Wines with the off odor of burning matches is a result of high concentration of
Sulfur dioxide
Hydrogen sulfide (H2S) gives off the odor of
Rotten eggs
The odor associated with wine that’s sat too long in a barrel or sur lie and absence of oxygen is
Rotten eggs, Hydrogen sulfide
Mercaptan is the result of the combination of sulfur and
ethyl mercptan
may form as a combination of sulfer and ethanol
ethyl mercptan smells like
garlic and onions
What 2 bacterias can live in wine?
Acetobactor and lactic bacteria
The odor of vinegar is _________ acid.
Acetic
The odor of rancid butter or spoiled cheeses is ____ acid.
Butyric
The odor of sauerkraut or goat is _______ acid.
Lactic
The odor of nail polish remover is ______ acid.
Ethyl acetate
The odor of crushed geranium leaves is normally caused by
an incomplete malolactic fermentation
The odor of band aid, medicinal, horsey or sweat is called
Brett
Brett is a yeast. T or F
True
Odors occurring in conditions that lack oxygen are termed
Reductive
