Wine Composition And Chemistry

Front 1

The Major Categories of chemicals in wine:

Back 1

Water
Alcohol
Acid
Sugar
Phenolic Compounds

Front 2

Water is what %

Alcohol is what %

Back 2

80-90%

10-15%

Front 3

Main Alcohol in Wine

Back 3

Ethyl Alcohol or Ethanol

Front 4

What % of wine is acid?

Back 4

1/2-3/4 %

Front 5

The Principle Acids in Wine are:

Back 5

Tartaric Acid
Malic Acid
Lactic Acid
Acetic Acid

Front 6

The most prevalent of the acids in grapes and wine, and the strongest.

Back 6

Tartaric Acid

Front 7

A sharp acid associated with green apples. Under ripe grapes are loaded with this type, but lot is lost during ripening. It is metabolized during respiration.

Back 7

Malic Acid

Front 8

This Acid is not found in grapes, but is created by lactic bacteria converting another acid--the process is known as Malolactic fermentation

Back 8

Lactic Acid

Front 9

The Acid of Vinegar. This Acid is very volatile, it readily evaporates and joins the aromas of the wine.

Back 9

Acetic Acid

Front 10

A minor component in grapes and a by-product of normal alcoholic fermentation

Back 10

Succinic Acid

Front 11

This Acid is not a normal component of grapes and thus wines normally do not contain any. It is sometimes added to increase the total acidity in a wine.

Back 11

Citric Acid.

Front 12

Wine is ph is typically what range?

Back 12

2.9-3.8

Front 13

What % of Sugar to grapes typically have at harvest?

Back 13

15-28%

Front 14

Grapes have roughly equal amounts of what two sugars?

Back 14

Glucose
and
Fructose

Front 15

Yeast converts Sugar into what:

Back 15

Ethanol

Front 16

Sweetness is often used to balance what?

Back 16

High Acidity in a wine

Front 17

C2H5OH

Back 17

Ethanol

Front 18

Phenolic Compounds are:

Back 18

Anthocyanins
Flavones and Flavonols
Tannins
Vanillin
Reseratrol

Front 19

Phenolics of a grape are concentrated in:

Back 19

Skin and Seeds

Stems

Front 20

Compounds that give wine a blue, purple, or red color--Redder in more acidic and bluer in less acidic

Back 20

Anthocyanins

Front 21

Yellow pigments found in white wines

Back 21

Flavones or Flavonols

Front 22

astringent or bitter compounds found in grape skins, seeds, and stems and in oak barrels that form the structure or the backbone of big red wines, protect the wine from oxidation, and create a drying sensation in the mouth

Back 22

Tannins

Front 23

an aromatic phenolic compound in oak that imparts the vanilla odor to barrel-aged wines

Back 23

Vanillin

Front 24

a compound believed to have several beneficial health effects in humans

Back 24

Reservatrol

Front 25

Over time what tend to polymerize or combine into longer molecule chaing that eventually become too heavy to stay suspended in the liquid.

Back 25

Tannins and Pigments

Front 26

Oxidized Alcohols that are formed when wine is exposed to air.

Back 26

Aldehydes

Front 27

The most common Aldehyde in wine and is formed by the oxidation of ethanol.

Back 27

Acetaldehyde

Front 28

Molecules that result from the joining of an acid and an alcohol. Represents the largest group of odiferous compounds in wine.

Back 28

Esters

Front 29

Dissolved oxygen promotes many chemical reactions through the process known as

Back 29

oxidation

Front 30

Why is sulfur and tannin added to wine?

Back 30

To absorb the free oxygen molecules and help the wine from oxidizing.

Front 31

A dissolved gas found in wine that gives sparkling wine its bubbles

Back 31

Carbon Dioxide
CO2

Front 32

An important preservative that is widely used to keep wines stable after fermentation and all wines contain at least a trace of it

Back 32

Sulfur

Front 33

A musty, moldy, rank odor found in wine-associated with contaminated wine corks

Back 33

TCA
or
2,4,6-tricloroanisole

Front 34

TCA has a high or low recognition threshold

Back 34

LOW

Front 35

An acrid smell like burnt matches that causes an unpleasant burning tactile effect on the tissus of the throat and nose

Back 35

Sulfur dioxide (SO2)

Front 36

The odor of rotten eggs which develops when a sulfur-rich wine sit too long in the complete absence of oxygen. This has been a potential problem for screw caps

Back 36

Hydrogen Sulfide (H2S)

Decanted will usually disperse the aroma

Front 37

Unpleasant odor smelling of garlic or onions. It is a combination of Ethanol and sulfur and is usually not remediable.

Back 37

Mercaptan

Front 38

The odor of vinegar

Back 38

Acetic Acid

Front 39

The odor of rancid butter or spoiled cheese.

Back 39

Butyric Acid

Front 40

A smell described as being like sauerkraut or a goat

Back 40

Lactic Acid

Front 41

The odor of fingernail polish remover

Back 41

Ethyl Acetate

Front 42

A sharp, pungent odor of mouse or wet wool

Back 42

Mousy

Front 43

An odor like crushed geranium leaves, normally caused by incomplete malolactic fermentation.

Back 43

Geranium

Front 44

Three Strains of bacteria that the greatest effect on wines:

Back 44

Lactic bacteria-responsible malolactic bacteria
Acetobacter-converts alcohol in acetic acid
Brettanomyces-causes the wine to have a mousy or horsy odor.

Front 45

Green-The odor of leaves

Back 45

Resulting from the use of immature grapes

Front 46

Oxidized

Back 46

An aldehyde odor-can make wines smell flat and lack fruit.
On purpose such as fino sherry can give them a nutty caramelized character

Front 47

Maderized

Back 47

A cooked or baked odor-to much heating or oxidization

Front 48

moldy odor

Back 48

results from moldy barrels or moldy grapes

Front 49

rubbery odor

Back 49

very low acid wines or excess sulfur

Front 50

stagnant

Back 50

stale water odor

Front 51

stemmy

Back 51

A bitter green odor of grape stems

Front 52

wet cardboard

Back 52

results from some of the filtering materials

Front 53

Yeasty and Leesy

Back 53

yeast cells remain in contact to long with the wine

Front 54

Reduction or reduced

Back 54

smells of rotten eggs, garlic, struck matches, cabbage or burnt rubber.
Not an accurate term but commonly used. Occurs when conditions lack oxygen.