One the other end of the fraudulent spectrum, wine fraud can also involve mixing toxic chemicals with wine, a combination that can be fatal. This may be performed in an attempt to increase the alcohol content of a low-alcohol wine or to make a type of wine more flavorful. When wine sellers or makers engage in this type of wine fraud, they are gambling with more than just scamming people out of their money: they are also gambling with people's lives. In 1986, an Italian winemaker mixed wood alcohol with his wine to increase the wine's potency. This resulted in the death of 23 people.

Perhaps the most common type of wine fraud is wine blending, an act that blends cheaper wine with more expensive wine and passes the wine off as authentic. This can involve a variety of wines. Wine makers have been caught blending everything from a cheap Rioja wine with Bordeaux to an expensive red Burgundy with inferior wine and selling the bottles at an inflated price.

To prevent wine fraud from ruining the industry, many of the world's major wine producers have begun taking preventative action. One preventive action involves placing serial numbers on bottles of wine, serial numbers that prove the wine's authenticity and value. This, unfortunately, does not provide protection for older wines that were bottled years ago.

For you the consumer, preventive action must also be practiced. Understanding that wine fraud exists is the first step in making sure you're never given a bottle that is blended, filled with toxic chemicals, or worth much less that you pay. If the label is particularly old looking, and appears to have been taken off another bottle and placed on yours, it's best to stay away from it. It is also best to only buy wine from reputed dealers. If the wine seller also asks if you want to buy a watch, it's best to turn away. Most importantly, never give up your yo-yo for a lousy old grapevine.