Common Wine Defects

Common 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:

Cork Taint

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.

Oxidation

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.

Heat Damage

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.

Chemical Reduction

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 occured. Such wines take on a sulfurous or funky aroma. This defect cannot be reversed.

Brett (brettanomyces)

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.