Cold Extremes

To allow a wine to become extremely cold, short of freezing, is in and of itself not harmful. Many wines, particularly whites, are in fact "cold stabilized" as part of the production process. These wines are chilled to near 38 degrees Fahrenheit for days, to assist in the precipitation of crystal "tartrates". The acidity, and thus tartness of a wine, can be significantly reduced through this process.The tartrate crystals fall to the bottom of the production tanks, and the wine is siphoned away.

On occasion a wine will exhibit tiny crystals at the bottom or side of the bottle, or if the bottles have been stored corks down, on the bottom of the cork itself. Many consumers mistake tartrates for glass, and discard a good bottle for fear of ingesting a piece of glass. If there is more than one, it is crystal shaped, rather than an obviously dangerous shard of glass, and it tastes very sour, you’ve got yourself a harmless tartrate crystal.

Freezing is another matter. Aside from the physical damage likely to occur as the expanding wine forces the cork up and out of the bottle, precluding any beneficial long term storage, the wine itself undergoes physical changes. I have on occasion had the unfortunate experience of tasting previously frozen wine, an experience the result of my forgetting a bottle laid in the freezer for a quick chill. Whatever uniformity of flavor and complexity the wine might have enjoyed often succumbs to a disjointed rendition of bad wine.