Common Defects & How to Detect Them
One of the most common wine questions I get is, "How do you tell if a bottle of a wine that you got at a restaurant is bad? I never know when to send one back."
Let me start by saying what does not constitute a bad bottle.
A bottle is not bad just because you don't like the wine. There are many variations in wine-making style, so a bottle that doesn't suit your preferences is not necessarily defective. Of course, the sommelier should help you select a bottle that's to your liking, but ultimately only you are responsible for your personal tastes.
A bottle is not bad just because the label is damaged. Most wine travels thousands of miles to get to you, and there are plenty of opportunities for bumping and grinding. Likewise, in a cellar where thousands of bottles are stored together, one bottle can break, leaking wine onto hundreds of others. This does not affect the wine inside the intact bottles.
A bottle is not bad just because it has little white crystals accumulated at the bottom or adhering to the cork. These crystals (called tartrate) are a natural by-product of unfiltered, unprocessed fine wines and are totally harmless.
A bottle is not "corked" just because it has bits of cork in it (all this means is that an inexperienced waiter pushed the corkscrew all the way through the cork, thus forcing pieces into the wine) or because it has an unsightly or even moldy cork. The term corked has a very specific meaning, which I'll explain in a moment.
There are essentially four things that constitute defects in a bottle of wine such that you should send it back: It can be corked, oxidized, maderized or refermented.
Corks are natural products, and some microorganisms like to eat them. A wine is properly said to be corked when it has come in contact with a contaminated cork during the aging process. The results of this contamination are almost always unmistakable: The wine will smell like a wet basement after a flood or dirty socks left in the hamper a little too long: moldy, nasty and not at all enticing to the taster. On the palate, it will be astringent, lacking in fruit, with a raspy finish. Sometimes you may even notice a paint-thinner quality.
Still, when you catch a wine in the earliest stages of being corked, there may be some doubt -- here, all I can say is that the more you taste wine, the higher sensitivity you will attain in identifying corked wines. Also, if a wine is served too cold, you may not catch the telltale aromas on the initial offering. This isn't your fault, and you are still well within your rights to send the bottle back once the defect becomes clear.
You cannot, however, discover a corked wine by smelling the cork. Many fine wines have issued from bottles with funky-smelling corks, and vice versa.
Oxygen is wine's invisible enemy, and when a wine gets exposed to air, it becomes "oxidized." The result is flat, lifeless wine that loses its pretty, vibrant fruit scents and tastes insipid -- it will likely remind you of vinegar. The trained eye will also often notice certain dullness in the color. In whites, it can be light to dark yellow or even brownish. It is much less obvious in red wines.
Heat is another destructive force exerted on wine, usually as a result of bad storage. When one says a wine is "maderized," it has been literally baked (this often happens in the holds of cargo ships as they cross the oceans in summertime). It actually tastes like Madeira and is reminiscent of almonds and candied fruits -- admirable qualities in dessert wines but unacceptable in dry wines. You may also notice, in the unopened bottle, that the cork is pushed partly out of the neck (due to expansion within).
Fine wine is a living thing, the product of controlled fermentation. Occasionally, some residual, dormant yeast will wake up, and a wine will undergo a second fermentation after it has been released and shipped. This manifests itself as effervescence, or fizziness, on the tongue. Of course, this is desirable in champagne (which is purposely refermented in the bottle in order to create the bubbles), but never in fine still wine.
It's difficult to learn to identify these flaws just by reading about them. Only experience and time will give you the training you need to spot every defect. But if you think a bottle is bad, ask the sommelier for confirmation. Don't be afraid -- at any reputable establishment the sommelier will not take a rejected bottle personally (not that you should care if he or she does). It is, after all, a statistical certainty that a certain percentage of wines will go bad through no fault of the restaurant. Some of these they can return to their distributors for credit; with others they will just take the loss. They compute their wine prices with the expectation that they will get some bad bottles. If they honestly think you're crazy and believe with all their hearts that the bottle is perfect, they will still take it back -- and maybe later have a glass themselves.
Recognizing Defected Wines
When should we return wine in a restaurant? More importantly, how do you tell if a wine is defected (corked) or if it simply tastes horrible?
We can usually identify a defected bottle before tasting it. Look for the following:
Clarity: Cloudy wine hints bacteria spoilage. The wine should be clear. There might be deposits (known as sediments) which are normal and provide no indication of their quality. Definitely return all cloudy wines!
Color: The color of the wine reflects its development. Oxidized wine (aged too long or exposed to oxygen) has tints of reddish-brown or amber-tawny for white wines. Oxidized wine tastes flat and stale.
Condition of the cork: If the cork is cracked, or penetrated by wine, the wine is most likely damaged.
Sometime, you might observe clear sugar-like crystals in the bottle of a bottle or glass. These are tartrates. They formed when the wines are stored in very cold temperature. They are harmless to drink. If anything, they indicate a good quality bottle - one that has not been commercially-treated during vinification.
Besides getting a solid sniff at the bottle, check for 3 smells that indicate potential defects:
Smell of moldy, musty smell of mushrooms or damped earth. This is caused by the Trichloronisole (TCA) in a corked wine. The smell might worsen with exposure to air.
Smell of vinegar or sherry. This would indicate high level of volatile acidity and oxidation.
Smell of rotten-eggs. These are caused by excessive hydrogen sulfide formed during the fermentation process. Though unpleasant, the wine is drinkable. One traditional remedy is to drop a copper coin into the wine to eliminate the odor.
Often, the wine will smell of burnt-matches when uncorked. This is the smell of sulphur dioxide, which was added in the bottling process to keep the wine fresh. There is no need to return the wine. The smell will go away after a few minutes of aeration.
An oxidized wine is flat and tastes like sherry/vinegar.
Definitely smell and taste the wine before going along with it at a restaurant. Statistics has it that one in 30 bottles of wines in the past 10 years are corked. Wine experts believe the statistics can be as high as one in every 10 bottles for aged wines. This is the reason that sommeliers offer you to smell the cork and also pour about an ounce for you to taste before you claim purchase of that bottle of wine.
More Wine Defects
Today’s wines are remarkably dependable. All the fuss surrounding restaurant wine service is a reflection of former days when 5-10% or more bottles were seriously flawed. But defects still exist and we need to know how to identify them. Some defects can be traced back to the winery and its methods. Others stem from mishandling of the wine after bottling. The older the wine is, the more serious these defects will be. There are only a handful of defects that you are likely to encounter:
Known in the industry as TCA (trichloroanisole), this chemical occurs naturally in some cork oaks and even a minute amount will utterly destroy a wine. The wine smells of wet newspaper or has no aroma at all. The flavor is absent and the wine is ruined.
A tiny amount of oxygen is necessary in wines kept for years. This is the primary rationale for cork-finishing, as natural cork allows for such micro-oxygenation. But too much oxygen ruins the wine and alters its color. White wines take on a deeper yellow color; red wines begin to turn brownish. Brownish wines are said to be “maderized,” after Madeira wines, which are naturally oxidized to a brown color. Oxidized wines are usually the fault of cork failure. If the cork is saturated to the top, be suspicious. This defect cannot be reversed.
When wines are shipped in unrefrigerated trucks in warm weather or stored under warm conditions in warehouses they take on a “cooked” character. They lose their freshness. Be careful about ordering wine to be shipped in hot weather. Also be aware that wines kept on display for months in comfortably warm wine shops may also suffer heat damage. This defect cannot be reversed.
This defect is the opposite of oxidation. The wine was so tightly sealed that micro-oxygenation was impossible and a process known as chemical reduction occurred. Such wines take on a sulfurous or funky aroma. This defect cannot be reversed.
This defect is caused by a wild yeast strain in the winery. A little Brett influence leads to warm, earthy, and barnyard-like aromas that are not necessarily a defect. But too much Brett leads to a distinctly funky and unpleasant wine. This defect cannot be reversed.
Defects are most often found in older wines and small production hand-crafted wines. Wines made in large quantities are very carefully monitored and are rarely defective.