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When & Why Does Unopened Wine Go Bad [Simple Explanation]

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There have been a few times in my life when opening a new bottle of wine has been rather unpleasant, with the wine somehow having gone bad inside the sealed bottle. So I set about finding out why this happens so that it hopefully doesn’t happen again. 

Any unopened bottle of wine will eventually degrade over years or decades. However, poor storage can expose a bottle of wine to oxygen, heat, or UV light and degrade wine in as little as a few hours. Wine can also be contaminated during production and be bad when brand new. 

Let’s take a closer look at when an unopened wine goes bad, why it happens, and what you can do to prevent it. 

When Does Unopened Wine Go Bad
When Does Unopened Wine Go Bad

TIP: If you want to check out the best refrigerator for wine storage, I recommend trying out Nutrichef (18 bottles) compressor wine refrigerator. You can find this refrigerator by clicking here (Amazon link).

When Does Unopened Wine Go Bad

Wine is like any other organic matter, it has a limited lifespan even when unopened. While it is accurate that wine lasts longer than other foods, it won’t last forever.

The vast majority of table wines are at their peak when bottling and should be drunk soon after purchase. These wines will have an expiration date printed on the bottle.

Wine is not immediately bad the moment the expiration date has passed. However, the quality of the wine will begin to decline as it slowly starts to decay. According to the data published by Healthline, this is how long you can expect table wine to last past the printed expiration date.

  • White wine: 1–2 years past the printed expiration date
  • Red wine: 2–3 years past the printed expiration date
  • Cooking wine: 3–5 years past the printed expiration date
  • Fine wine: 10–20 years, appropriately stored in a wine cellar

A critical factor in how long your unopened wine will last is how it is stored. Even table wine can last longer than the recommended times listed above if it is correctly cellared in a cool, dark place and the bottles are kept on their sides so the cork cannot dry out.

I have always kept my table wines cellared in the same way that I do my fine wines. I can remember when I was packing up to move in 2013, I discovered an $8 bottle of 2001 KWV Roodeberg that I had forgotten about among my fine wines. It tasted delicious, but I could hardly detect any tannins on the palate.

Why Does Unopened Wine Go Bad

Why Does Unopened Wine Go Bad
Why Does Unopened Wine Go Bad

The most common reason that unopened wine goes bad is that it has a wine fault. Some wine faults occur during winemaking or bottling, while others result from incorrect storage practices.

As many as 1 in 75 bottles have one of the seven common wine faults. However, even if wine is bottled with a wine fault, it will likely still be drinkable if it is opened and consumed before it properly manifests. That is part of why the more mass-produced table wines have the expiration dates I mentioned above.

In her book, also available on Amazon, Madeline Puckette lists the seven common wine faults and how to detect them. She makes the wise recommendation that if we come across a wine that has gone bad, we should use the learning opportunity to pour a little into a glass and sniff it.

That way, we can detect bad wine quickly if presented to us at a restaurant. Here are those seven common wine faults and what to look for.

Oxidized Wine

Oxidation is when a wine is contaminated by too much exposure to oxygen in the same way that cut fruit turns brown when left out for too long. White wine becomes oxidized quicker and easier than red wine as the tannins slow the oxidation process.

The most common cause of a closed bottle of wine becoming oxidized is a problem with the closure that allowed the wine to be exposed to oxygen.

This can happen in one of two possible ways. The first is that the wine had a faulty closure during the bottling process and was not adequately sealed.

The second and more common way your unopened wine can become oxidized is if you store your wine standing upright. The cork will dry out and shrink, which breaks the airtight seal of the closure allowing the wine to be exposed to oxygen. 

The solution is to store your wine with the bottle on its side to keep the cork damp. If I am at a wine store where the wines are all standing upright, I will try to look under the plastic cap seal to see if the cork still looks good or has dried out and shriveled.

To slow the oxidation of wine once it is open, consider using a vacuum pump with rubber stoppers like the Vacu Vin Wine Saver (available on Amazon).

How To Recognize Oxidized Wine:

Oxidized wine loses its brightness and turns brownish. It will also smell and taste similar to vinegar mixed with caramelized apples.

The way I taught myself to recognize oxidized wine was to leave some wine in a bottle for a week to oxidize. The following week I opened an identical bottle and tasted the new wine alongside the oxidized wine.

I only ever needed to do that experiment once, and my palate is still attuned to wine that is even just slightly oxidized more than two decades later.

If you have wine seeping through the top of the cork, you can be sure that the wine in the bottle will be oxidized.

Cork Taint (TCA)

Cork taint is the common term for TCA or 2,4,6-Trichloroanisole. It is a chemical that got into your bottle of wine somewhere during the production process.

The most common source of TCA is the cork, though it can also come from oak barrels or the processing lines at the winery. You can read more about the effects of cork taint on wine here on Pinot Squirrel in our article called: Can You Drink Wine With Cork In It? 

TCA contaminates as much as 2% of all wine bottled using natural cork. Because TCA contamination happens in the production process, it is never a single bottle or maybe two that gets ruined. It is usually the entire batch of the production run that is contaminated.

How To Recognize Cork-Tainted Wine:

Cork-tainted wine has a distinct damp, moldy smell. The most common smells associated with TCA contamination are wet newspaper, moldy cardboard, or wet dog.

TIP: I wrote this great article on how to store wine with a cork that you will undoubtedly learn from. This article will be your resource to learn how to store wine without a cork.

Sulfur Compounds

Look at the label of any bottle of wine, and you will likely see the words “contains sulfates”. That is because sulfur is added to nearly all wine to stabilize it after fermentation. Aside from that, dihydrogen sulfide (H2S) is a naturally occurring byproduct of fermentation. 

Nearly all sulfur compounds “burn off” within 15 to 20 minutes after opening a bottle, especially if the wine has been decanted.

How To Recognize Sulfur-Tainted Wine:

If you open a bottle and detect the smell of a struck match or cooked cabbage, that is the H2S sulfide that will dissipate after about 20 minutes.

If you wait 20 minutes and you get smells of rotten egg, garlic, or burned rubber, you have a sulfur-related flaw in your wine called mercaptan that will not dissipate no matter how long the wine is open. 

Mercaptan-tainted wine is essentially undrinkable. It must be noted that the maximum levels of mercaptan detected in wine are, at most, only 10% of the concentration where the contamination becomes toxic.

Secondary Fermentation

Secondary fermentation is when the wine continues fermenting after it has been bottled. This is when there is still some residual sugar in the wine, resulting in fermentation.

It is also common in wines listed as sulfite-free, and the added sulfites stop the fermentation and stabilize the wine.

Some winemakers deliberately bottle wine in a way that promotes refermentation as part of their style.

How To Recognize Refermentation In Wine:

When a wine has referred, it will have some fine bubbles and make a fizzing sound as you extract the cork. Secondary fermentation does not make wine undrinkable. The bubbles will dissipate if you leave the wine open or decant it.

TIP: A critical aspect of keeping wine for long periods is the correct temperature and humidity. Check out this complete guide on controlling humidity in the wine fridge and the most common reason your wine cooler is not cooling in this article.

Heat Damage

Heat ruins the taste of wine. If you leave a case of wine out in the baking sun for a few hours during summer or store your wine next to a roaring fire during winter, you will essentially cook your wine and alter the taste.

How To Recognize Heat-Damaged Wine:

Heat-damaged wine will smell like jam or a wine reduction sauce. One way to quickly recognize heat-damaged wine is that the pressure from the heat will usually push the cork part-way out of the bottle.

TIP: If you want to check out the best refrigerator for wine storage, I recommend trying out Nutrichef (18 bottles) compressor wine refrigerator. You can find this refrigerator by clicking here (Amazon link).

UV Light Damage

Delicate white wines are prone to UV light damage if stored close to a window and exposed to direct sunlight.

How To Recognize UV-Light Damaged Wine:

UV light damage makes wine smell like a wet wool sweater.

TIP: Many people wonder about the best way to store wine long-term. This article identifies if the wine should be stored in the dark. You can find out how sunlight affects wine while stored in this article.

Microbial and Bacterial Taint

Many microbes live during the fermentation process of wine and are part of what gives the wine its complexity of many layers of aromas. If a colony of microbes grows too aggressively, it can overpower the wine – like adding too much salt to a dish.

This can only be detected through the tasting process by an experienced palate, as what sommeliers call mousy. The most easily recognized microbial taint is when you breathe out after swallowing a sip of wine and get a clear hay bail smell.

Conclusion

Now you know the seven ways unopened wine can go bad and how to detect each one. We have also covered what you can do to prevent your wine from going bad so that you can enjoy your favorite wines for years or decades.

TIP: For a complete list of wine products and accessories I really love, check out this page. You’ll find my recommendations for wine refrigerators, decanters, and aerators and the best place to buy wine online. Click here to see the complete listing.