Wine Faults Flashcards
4 main categories of wine faults
2,4,6—trichloroanisole (TCA)
Odors from sulfur
Odors from bacteria
Other odors
How 2,4,6-trichloroanisole (TCA) is produced
What is tastes like in wine, with most characteristic first
Terms used to describe it (2)
Is it dangerous to drink?
Myth about where it comes from, and where it really comes from.
It is produced from the interaction of mold with the wine
1—musty, moldy odor, like an old basement
2—in milder cases, wine will seem less flavorful or muted
Corked, or cork taint
No
It is not just from the cork. The mold grows on the bark of the cork tree, on wine-making implements, in barrels, or in the winery itself (walls, boxes, etc).
Note about TCA and seals used in wine
Note about prevalence of cork taint, with statistic
Note about TCA potency, with statistic
TCA can be persistent anywhere in the winery and can occur in wine with screw caps or artificial corks
Incidence of cork taint has fallen but still affects 1-8% of wines produced every year.
Has extremely low threshold recognition, meaning it is noticeable at small concentrations. Most can detect it at 2-7 parts per trillion.
3 fault odors resulting from sulfur compounds, with chemical formulae for first two
Sulfur dioxide (SO2)
Hydrogen sulfide (H2S)
Mercaptan
How sulfur dioxide effects wine experience (2)
What these effects are directly related to, and how
1—will cause an acrid smell, like burnt matches
2—can cause unpleasant burning sensation in throat or nose
They are r/t pH. The more acidic the wine, the more pronounced these effects will be.
What hydrogen sulfide (H2S) tastes in wine
General way it appears in wine
2 specific examples of this way
Rotten eggs
Develops when a sulfur-rich wine sits for too long in the complete absence of O2
1—when wine with a lot of yeast sediment rests too long in the barrel or tank
2—when screw caps, which are more impervious to O2, are used instead or screw caps
How is ethyl mercaptan formed
What it smells like
How mercaptan odor is used commercially
Not about seriousness of this fault
It is a combination of sulfur and ethanol
Garlic or onions
Added to natural gas to help people detect a leak
It can be confused with hydrogen sulfide, but it is a more serious defect and is less remedial than other two sulfur-related faults
2 major bacteria that can survive the acidic environment of wine
What these bacteria do generally, with an especially dangerous example
What lactic bacteria does specifically
What acetobacter does specifically
Lactic bacteria
Acetobacter
They attack various chemicals in wine and changes its composition. They can produce CO2, which can make bottles explode.
Lactic acid produces malolactic fermentation, incl unintentionally
Acetobacter converts alcohol to acetic acid
Main odors produced by the following bacteria:
Acetic acid
Butyric acid
Lactic acid
Vinegar
Rancid butter or spoiled cheese
Sauerkraut or a goat
What kind of fault generally is ethyl acetate in wine related to?
Two scents associated with it
Chemical reaction causing it
Term used to describe this reaction
Bacterial odor
1—nail polish remover
2—airplane glue
An ester formed by the combination of ethanol and acetic acid
Ascensence
What kind of fault is geranium associated with generally?
What does it smell like
What causes it (2)
Bacterial odor
Crushed geranium leaves
1—incomplete malolactic fermentation
2—improper breakdown of the preservative sorbic acid
What is “Brett” short for?
What is it
Three things it can do to wine
Differing opinions regarding it
Brettanomyces
A member of the yeast family that can infect a winery and some or all of the wines produced there
1—give wine a sweat or horsy odor
2—give wine a band aid-like or medicinal odor
3—dead the wine’s primary flavors
It is acceptable to some in small amounts, not acceptable at any amount to others.
Describe how “green” wine fault smells, with cause
What causes moldy wine fault
Two things associated with rubbery wine fault
What does stagnant wine fault smell like?
Odor of leaves, usually resulting from use of immature/under-ripe grapes
Mold in grapes or barrels
1—more common in low acid wines
2—excess sulfur
Stale water
Describe process of oxidation in wine, including chemical component and outcome
Desirable character of this process, with wine type associated with it
Negative things it can do to other types of wine (2)
Oxygen dissolved in wine from contact with air will react with phenolic compounds in the wine and can create acetaldehyde.
Can create a nutty, caramelized character associated with fino Sherry
1—cause lack of fruit character
2—browning of wine
What does maderized wine fault taste and smell like.
Two things that cause maderized wine fault.
When it is acceptable, with example
What does wet cardboard wine fault smell like?
2 things that cause it
Cooked or baked
1—oxidation
2—excessive heat
In wines that are heated, like Madeira
Papery, chemical odor
1—cork taint
2—misuse of filter pads or materials
