Chapter 1 Flashcards
Alcohol % in wine
10-15%
Ethyl Alcohol/Ethanol
Primary result of alcoholic fermentation, and main alcohol component. Also, it is a volatile compound, which means it evaporates easily and carries the aromas to the nose.
Other types of alcohol that occur in smaller amounts include
Glycerol, methyl alcohol, and group compounds known as fusel alcohols, or higher alcohols.
How does alcohol content affect the pallet sensation.
It is one component that contributes to the body, and weight of the wine in your mouth. Higher alcohol content means a fuller bodied wine. It can also contribute to the tears in the glass being thick and slow moving.
Acid % in wine
0.5%-0.75%
The principal acids in wine include
Tartaric acid, Malic acid, Citrus acid, Lactic acid, Acetic acid, and Succinic acid.
Tartaric acid
Most prevalent in both wine and grapes, as well as the highest pH. Forms crystals at low temperatures which lowers the acidity in the wine, but it’s not considered a fault.
Malic Acid
Sharp tasting, associated with green apple. Under ripe grapes in a cooler climate are typically higher in Malic acid, and lower as the grapes ripen. Malolactic fermentation is usually used when wines are too high in the acid.
Citric Acid
A very small level of this acid in grapes, and cannot be detected by taste or smell. This acid is sometimes added to increase acidity, but not in quality wines.
Lactic Acid
Not found in grapes, but created in wine by lactic acid bacteria which convert malic acid into lactic acid during malolactic fermentation. Wines that undergo this process tend to be softer and smoother, with a creamy texture and in some cases a “buttery” aroma. Also created during primary fermentation in small amounts.
Acetic Acid
Found in most types of vinegar, and typically created in low levels during fermentation. This acid is volatile, so it readily evaporates and adds to the aromas of the wine, particularly in red wine. However in high concentration, which is typically the result of acetobacter causing chemical reactions between ethanol and oxygen, wine can become very unpleasant.
Succinic Acid
Sharp, slightly bitter, slightly salty flavor. Very minor component, a by product of normal alcoholic fermentation.
What do we use to describe the acidity level in wine
Total Acidity (TA), and pH level
Sugar levels in wine
15%-28% Roughly equal amounts of glucose and fructose.
Glucose and Fructose role in fermentation
Yeast converts these sugars into ethanol, turning grape juice into wine. If allowed, yeast would turn the wine completely dry, however even “dry” wines have trace amounts of sugar, as grapes have teeny amounts of unfermentable sugars.
