Wine Faults

Question 1

What are three causes of faults in wine?

Answer 1

winemaking errors, improper storage, bad luck

Question 2

What is cork taint and what does it do to the wine?

Answer 2

2,4,6-Trichloroanisole (TCA)

It’s caused by interaction between the wine and mold that grows on cork trees, or in the winery itself, which generate the chemical TCA.

It gives wine a damp, musty or cardboard odor. When this occurs, the wine is said to be “corked.”

Question 3

How prevalent is cork taint?

Answer 3

1% - 8% of all bottles

Question 4

At what concentration can most people detect TCA?

Answer 4

2 to 7 parts per trillion

Question 5

What are three examples of off-odors caused by sulfur compounds?

Answer 5

Sulfur dioxide, Hydrogen sulfide, Mercaptan

Question 6

What does excessive Sulfur dioxide do to a wine, and what other element in the wine is it related to?

Answer 6

SO2 in high concentrations can express as an acrid odor, similar to a burnt match.

It is directly related to Ph–the lower the Ph, the more pronounced SO2 will be be.

Question 7

What are common causes of excessive Hydrogen sulfide?

Answer 7

A sulfur rich wine sitting for too long in the complete absence of oxygen, gives it a rotten egg smell.

Large amount of yeast sediment and stelvin closures can contribute to the problem.

Question 8

What causes mercaptan to form?

Answer 8

The combination of sulfur and ethanol, which can express as garlic or onion, and is very difficult to remediate.

Question 9

What are the two most common types of bacteria found in wine?

Answer 9

Lactic bacteria, which initiates malolactic conversation, and acetobacter, which convert alcohol into acetic acid.

Question 10

What are five off-odors associated with bacteria?

Answer 10

Acetic acid - vinegar, the term volatile acidity and ascensence are used to describe this
Butyric acid - rancid butter
Lactic acid - goat, formed from MLC
Ethyl acetate - nail polish remover, an ester formed from an ethanol and acetic acid
Geramium - crushed flowers, can result from incomplete MLC

Question 11

What yeast often found in around the winery can contribute odors of barnyard or bandaid to a wine?

Answer 11

Brettanomyces, often considered desirable in small quantities.

Question 12

What causes green odors in a wine?

Answer 12

Under-ripe grapes

Question 13

How does oxidation effect wine?

Answer 13

It may lack freshness or fruit, or contribute a nutty, caramelized note, as well as acetaldehyde, which has a tangy characteristic. Can be intentional.

Question 14

What term describes a wine with a cooked or baked character?

Answer 14

Maderized - acceptable in Madeira, which is intentionally produced in this manner.

Question 15

What are three other wine flaw descriptors?

Answer 15

Moldy, rubbery, stagnant

Question 16

What does “stemmy” describe in connection to wine?

Answer 16

The green bitter characteristic of grape stems.

Question 17

What can cause “wet cardboard” smell?

Answer 17

TCA or misuse of filtering material.

Question 18

What does “reductive” mean?

Answer 18

In winemaking, the absence of oxygen, which can express as rotten eggs, struck match, burnt rubber. Not always a flaw.

Question 19

What does “yeasty” or “leesy” mean?

Answer 19

A pronounced odor of yeast, which develops if a wine spends too long in contact with the dead yeast sediments at the bottom of the vessel. Not always a flaw.