How Do I Check for Signs That Wine Has Gone Bad in Storage?

A healthy cork will be slightly discolored from the wine, while a spoiled wine will usually have a crumbling, soaked-through cork. Photo Credit: Pixabay CC user Couleur

The distinctive smells of a wine that has gone bad—often reminiscent of moldy wet newspaper and acetone—are the last things anyone wants to experience when they uncork a bottle of fine wine. However, you can sometimes spot the telltale signs that wine has gone bad in storage before you even open the bottle. Knowing how to spot common red flags is a great way to avoid buying spoiled bottles on the secondary market. It can also warn you of potential storage issues so you can correct any problems before they ruin the other bottles in your collection. At the very least, knowing the signs that a wine has gone bad will save you from getting a mouthful of soggy newspaper when you were expecting an elegant Bordeaux. Here’s how to identify a bad wine before or after you’ve opened the bottle. 

The First Signs That Wine Has Gone Bad in Storage 

There are many types of wine faults, such as too much sulfur or Brettanomyces yeast (Brett), but what wine drinkers often mean when they say that a wine has gone bad is that it is corked, which usually means it is tainted with the chemical 2,4,6-trichloroanisole or TCA (although other compounds can also cause this problem). It’s easy to spot a corked wine after you smell it in a glass or take your first taste. In addition to wet newspaper, corked wine has also been described as smelling like wet dog or musty old books. The taste is even more off-putting, if you can hold your nose long enough to take your first sip. A wine that’s corked sometimes tastes just like it smells, but it can also taste very astringent. Spoilage reduces the fruit flavors in the wine, leaving behind more of the bitter or acrid flavors from the tannin and acid.

Yet these are not the first signs that wine has gone bad in storage. You may be able to save yourself the experience of smelling or tasting these wines by inspecting the wine bottle before you pull out the cork.

Step 1: Look at the Cork’s Position

First, look at where the cork is situated. If it’s bulging from the top of the bottle slightly, it’s a sign that the wine might have suffered from heat damage, meaning its flavors won’t be as fruity and delicate as they should be. However, a raised cork is also a sign that the winemaker might have sealed the bottle improperly. While this is most commonly a problem for producers that use inexpensive or synthetic corks, occasionally even the most valuable wines in the world have this issue. A bad seal will either look like the cork has too much space around it, or it will be so tight that you have difficulty pulling it out of the bottle. In the first case, the wine will likely be prematurely oxidized; too much oxygen will leak into the bottle too quickly, making the wine age and spoil within a very short time. In the second case, the opposite happens. The wine doesn’t get enough oxygen with the firm seal, preventing it from slowly aging and developing new flavors.

Step 2: Analyze the Wine’s Ullage 

In addition to the cork, look at the wine’s ullage (the space between the cork and the wine). In a young wine, the liquid will appear to almost touch the cork, and generally, the higher the ullage, the better condition the wine will be in when you open the bottle. In wines that are more than 15 years old, the ullage can start lower, at the top of the bottle’s shoulder, but if the liquid dips below the upper shoulder, it’s generally a sign of premature oxidation. 

Tips to Remember Before You Buy

Follow the two steps above whenever you buy wine on the secondary market (or even directly from a producer). If you can’t see the wine in person, look at photographs of the bottle or ask the seller to describe the cork and ullage condition. This can potentially save you from buying a wine that has either spoiled prematurely or won’t mature properly.

However, if you’re checking your own wines and notice these telltale signs, open the bottle to confirm your suspicions. It’s possible that a poorly positioned cork hasn’t tainted the wine completely yet, and you don’t want to throw away a perfectly good bottle by mistake. 

Trust Your Senses of Sight, Smell, and Taste 

Just because the cork and ullage look normal doesn’t necessarily mean the wine is in good shape. The wine could have a flaw that isn’t easy to identify by looking at the bottle alone. Follow these four steps after opening the bottle and before you take your first sip.

Step 1: Check the Base of the Cork

When you remove the cork from the bottle, check its base (the part touching the wine); it should be only slightly stained from the liquid. Corks that appear to have soaked up a significant amount of wine or that crumble to the touch are possible signs that wine has gone bad in storage. Soggy corks are those that were not well sealed to the bottle, allowing liquid to seep up around the edges. Likewise, crumbling corks are not dense enough to protect the wine from oxidation, increasing the likelihood of a spoiled wine. However, keep in mind that some older bottles of wine, particularly fortified wines like port, naturally have crumbly corks. The corks wear down over time, so don’t be too worried if the cork in a 50-year-old bottle of Taylor Fladgate crumbles a bit. The wine inside is likely perfect.

Step 2: Look at the Color

Pour yourself a glass and look at the color; it should look like other wines of that variety and from that region, with only slight variations in hue. For example, Cabernet Sauvignon can range from a bright ruby to an inky purple depending on the producer, vintage, and where it was made. However, if the wine is brown or tawny, that should give you pause. Brown coloration is a sign of oxidation in both red and white wines of all varieties. However, this is a normal color in aged wines and is actually a sign that the wine has aged well. As a general rule, if the wine is no more than a few years old, it shouldn’t appear tawny or brown at all, but if the wine is a few decades old, this color is a good sign. 

Step 3: Smell the Wine 

As for smell, your wine’s bouquet will vary depending on the variety, style, and age. For example, it’s not uncommon to smell a slightly funky barnyard note in Côtes du Rhône blends. This is not a serious wine flaw. Instead, it’s caused by Brett and at low or moderate levels is completely normal—even desirable—in these wines. Abnormal smells are those of mold, wet newspaper, wet dog, or vinegar; these are signs of a corked wine or a wine that has reached its natural expiration date. Another bad sign is a cooked fruit smell in a very young wine. This aroma typically only develops as a wine ages, so if you’re identifying it in a wine that’s only a year or two old, it is a sign that the wine has been exposed to too much oxygen far too quickly.

Step 4: Try the Wine

Even if you get through this stage and your wine still looks and smells normal, you’re not quite out of the woods yet. It is time to taste the wine. Any wine that tastes very bland or that has a strong vinegar or chemical taste has gone bad in storage. You can spot this easily because you’ll have no desire to take more than one sip of wine. Other red flags are less obvious and unpleasant, but equally problematic. For instance, a dry red wine should never taste sweet, and if it does, it has likely suffered from heat exposure. Still wines should never have carbonation; if they do, it’s a sign that the wine has gone through a secondary fermentation in the bottle.

Getting a taste of corked wine or wine with another serious flaw isn’t the most pleasant experience, but it’s unlikely to harm you. You can safely drink wine that’s gone bad in storage—if your taste buds can stand it.