Whether a bottle of wine was forgotten in the freezer or purposefully placed for preservation, there are several possibilities for the future of the wine.
If the bottle is just about full, the wine will expand, which can push out the cork or break the airtight seal of a screw cap. In the worst-case scenario, the pressure might cause the bottle to break. In most cases, the wine will taste pretty much the same and remain unaffected besides a few floating crystals after the wine has returned to its liquid state.
The Science Of Tartrates
A tartrate is nothing more than the solid form of tartaric acid, one of the three main acids in wine. Tartaric acid, malic acid and citric acid all work together to give each wine its own, unique color and flavor. Tartrates also work to prevent wine from spoilage caused by bacteria.
Tartaric acid primarily contributes to the pH of a wine and contributes to wines sour and acidic flavors. The amount of tartaric acid decreases as grapes ripen, and there are more tartrates contained in grape stems. Picking grapes before they are ripe or fermenting the wine with the seeds and stems are both methods to increase the amount of tartaric acid in a wine.
Tartaric acid can separate out from wine and solidify into tiny crystals when the temperature drops. Most wine sediment can be attributed to tartrate, and the rest is assumed to be unspent yeast. White wines are said to be more susceptible to tartrates. This might be because red wines are not often served cold or exposed to refrigeration during the wine-making process, allowing tartaric acid less opportunity to separate.
Most American wineries process their wine through cold stabilization in order to filter out tartrates by chilling the wine long before it is bottled and shipped to the shelves. After pouring out the wine, winemakers are even able to save the residue to package and sell as cream of tartar. Most importantly though tartrates are totally safe and won’t hurt you, even if they do look a bit like broken glass.
Freezing Wine For Preservation
Most instances of freezing come from the wine drinker trying to save the bottle to enjoy at a later date. Oxidation nearly stops when a wine is frozen, which is why dropping temperatures work to preserve the flavors in the wine from going bad and tasting like vinegar.
After defrosting, the wine might undergo subtle changes. Alcohol can separate out from wine in the freezer because the two have different freezing points. Be sure to give a good swirl to the wine to integrate all of the contents evenly. The flavors might be a tad less sweet and the aromas might be a slightly muted, but the average wine drinker will not notice a difference. Tartrates will likely be floating around too. If wine diamonds are a hindrance to your wine drinking experience, you can do your own form of cold stabilizations by running the wine through a filter made of cheesecloth.
While most of the time it is safe to preserve wines without it having drastic effect on the flavor, not all wines can be frozen. Fine red wines can lose flavors past its freezing point that might not reintegrate very well in returning to a solid state. The flavors in all aged wines are very fragile. Sparkling wines will simply explode if left in the freezer long enough.
There are much better ways of saving wine for later than freezing. Technology has allowed wine lovers to preserve their favorite bottles by injecting an inert gas in the wine bottle before recorking in order to slow the oxidation process. Malleable, plastic discs known as wine shields can be slipped into an opened bottle to float on the surface of the wine, blocking any exposure to oxygen. Try recorking or using a wine stopper for good measure.
How To Prevent Using The Freezer
Folks also utilize the freezer for a quick chill when the fridge is just not fast enough. In this case, the frozen wine is a result of a forgotten bottle. As explained previously, the wine and its flavor will likely be unchanged. Regardless, there are avenues to avoid the possibility of a frozen wine being frozen at all because it will not go near the freezer.
To avoid any possibility of frozen wine, do not use the freezer at all. Fill a bucket with half ice and half water. Throw a few teaspoons of salt in the mix. Give a good stir. The added salt lowers the freezing point of water and the contents get colder. Stick the bottle in the mix and it will cool quickly.
If a bucket, ice and salt is not your speed, pick up a bag of grapes the next time you purchase a bottle at the grocery store. Freeze the grapes. When you are ready to drink, pop a few in the glass with the wine. Unlike ice cubes made of water, grapes will not dilute the flavor of wine. Not to mention, it makes for a lovely garnish when company is over.
If you feel that your frozen wine is no longer enjoyable as a beverage, try reusing it in another way. Wine can serve various purposes in the kitchen. Leftover wine frozen cubes can come in handy for experimenting with cooking. Pour in the tray and let it freeze. Do not forget they are wine cubes. When you are ready to cook, throw a few cubes on the pan to let them melt and sizzle. Some masters in the kitchen even make jellies, marinades and dressings out of their preferred flavors. Cheers!