Ch. 2 - Wine Faults

Question 1

What is TCA?

Answer 1

2,4,6- Tricchloroanisole
One of the biggest concerns in terms of wine quality
control is the incidence of a musty, moldy odorsimilar
to that of a dank basement-occasionally
found in wine.

Question 2

What causes TCA?

Answer 2

A mold that can grow on and in the bark of the cork oak tree, on the winemaking implements, or even in the winery itself. This mold readily interacts with other compounds to generate the chemical 2,4,6-trichloroanisole, also known as TCA.

Question 3

What odors result from Sulphur compunds?

Answer 3

• Sulphur Dioxide (SO2)
• Hydrogen Sulphide (H2S)
• Mercaprtan

Question 4

What aroma is peculiar to sulphur dioxide?

Answer 4

• Burnt matches
• The sensory effects of S0 2 are directly related to pH. The more acidic the wine, the more pronounced the sulfur dioxide will be.

Question 5

What causes Hydrogen Sulphide related aromas to develope in wine?

Answer 5

When a sulfur-rich wine sits too long in the
complete absence of oxygen, it may develop the
odor of rotten eggs.

Question 6

What is mercaptan?

Answer 6

Ethyl mercaptan may form as a combination of sulfur and ethanol. This results in a very unpleasant odor, sometimes described as smelling like garlic or onions.

Question 7

Which bacteria can survive highly acidic enviorments in wine?

Answer 7

Lactic bacteria and acetobacter.

Question 8

Name a few typical bacteria-related off-odors.

Answer 8

• Acetic acid: The odor of vinegar.
• Butyric acid: The odor of rancid butter or spoiled
cheese.
• Lactic acid: A smell described as being like
sauerkraut or a goat.
• Ethyl acetate: The odor of fingernail polish
remover or model airplane glue
• Geranium: An odor like crushed geranium
leaves, normally caused by incomplete malolactic
fermentation or the improper breakdown of the
preservative sorbic acid.

Question 9

What is Brett? What off-odors does it cause?

Answer 9

Brett: Short for Brettanomyces, “Brett” is a member of the yeast family and can infect a winery and some or all of the wines made there. Brett causes a “sweaty” or “horsy” odor, or it may simply deaden the primary flavors in a wine.

Question 10

What off-odors does reduction or reductive wine cause?

Answer 10

A term that refers to a smell of rotten eggs, garlic, struck matches, cabbage, or burnt rubber. These odors occur in what is known as reductive conditions: conditions that lack oxygen.