Common wine faults: ‘Brett,’ sulfur dioxide
Judging the quality of a wine is essential to its enjoyment, and the understanding starts with a simple question you can ask yourself when smelling your glass. Does this wine smell clean?
Many years ago a poor quality, unclean wine was more common. The reasons varied: it could be from an unruly yeast strain; the winery having no control of temperatures during fermentation; unsanitized cellars teeming with bacteria (this list can go on and on). But with today’s technology and winemaking expertise it is rare to find a wine fault occurring specifically from the winery.
But faults do occur. Here’s how to identify some of the most common.
Corked wine: Of the many faults that occur, a tainted cork is one of the most likely. A corked wine, or cork taint as the flaw is also called, is one of the most obvious defects to detect. The wine will have a musty odor similar to a moldy, damp basement, wet cardboard and newspapers, or even a stinky sweaty locker room. Cork taint is one of the most common wine faults and is thought to affect up to 10 percent of all wines bottled in the world. It is caused by a cork infected with a fungus producing 2,4,6-trichloroanisole (the technical term) but generally referred to as TCA. When this chemical comes in contact with a wine it imparts a musty and moldy odor. Research suggests there may be a connection between the process of chlorine bleaching the corks and the development of the fungus.
The frequency of cork taint led many producers to seek alternate closures such as screw caps and synthetic corks. If you don’t have a cork you can’t have cork taint.
Brettanomyces: This long-winded word is also known as “brett.” It’s simply a yeast. It is controversial in some circles to call it a wine flaw, because in some cases it is winemaker’s intention. In small amounts it can add a complexity to wines, but if too much is present, it can make a wine smell horrible. It can be found in white wines but generally it is more of an issue for reds. Unpleasant smells caused by brett include a sweaty saddle, a stable, barnyard, Band-Aids, a horse and, at low levels, it can be spice, cloves, smoke or leather. The most common way of removing the yeast is to use sulfur dioxide.
Sulfur dioxide: There’s no mistaking this fault, as it is best described as the smell of a recently struck match. Sulfur dioxide is a winemakers’ antiseptic and is used in almost all winemaking. But when too much is used, the result is a fault. It is common in inexpensive, sweet and semi-sweet wines because the addition is higher in an attempt to stop the wine from re-fermenting. It was a very noticeable fault many years ago in inexpensive German wines. Today the industry is using much less sulfur and this fault is rare.