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How to Spot Faulty Wine

How to Spot Faulty Wine

Whether you’re opening a bottle at home or enjoying a glass while out to dinner. Wine is a staple in most cuisines and can be the perfect complementary flavor to a meal. However, not all wine is made or handled properly. This results in flawed wine.

In this article, we’ll break it down by what to look for in appearance, aroma, and flavor. That way, a bad wine won’t ruin your evening.

Common Ways Wine Goes Bad

Like any consumable product, there’s always the possibility of wine going bad or having flaws. Some are subtle, and the average wine drinker may not notice.

While others will be blatantly obvious and leave you questioning what happened to the bottle you just opened a few days ago.

It turns out that a few different things can happen during the wine-making process, shipping, or even at home. Most reasons for flawed wine come from unwanted chemical reactions happening throughout the process. These reactions include:

From here, we can start to look at how these unwanted reactions show themselves in wine.


One of the ways you can tell if a wine is faulty is simply by looking at it. That being said, there are a few specific things to look out for. These will give you a good idea if the wine is drinkable or not.


This is the easiest difference to spot. Red wines can range from brownish-red to ruby to an almost-purple or maroon color. But a wine that has gone bad will have lost its luster, and the color will appear almost faded.

Depending on the cause, it will most likely have a brownish-tinge to the appearance. This is often the result of oxidation. White wine is more susceptible to this because they lack the tannins (a chemical compound) that red wine has. A brownish tint will also be more prevalent in white wine.


A wine that has gone bad will also have a change in its condition beyond the color. The somewhat transparent liquid will appear hazy or cloudy. It may give off a look similar to murky water.

When you look at the glass or bottle that holds the wine, you may also see what looks like a film. This film is created by bacterial growth and gives you an easy way to spot the fault.


Another tell-tale sign of bad wine is bubbles in an otherwise non-carbonated beverage. Of course, we know some wines are meant to be bubbly, like several champagnes, Cava, or Prosecco.

These are processed with added carbonation on purpose. But still-wines that are most commonly consumed should not have any bubbles.

If you take a sip before noticing the unwanted carbonation, you’re likely to be met with a sour and acidic taste. Very much unlike the sweet-tart flavor that a traditional bubbly should have.


Whether you’re a novice wine drinker or you hold a Sommelier certification. Aroma is a major part of our ability to taste and understand flavors.

The aromas that come from wine are complex, and as you become a more experienced wine drinker, they will come into play a lot more. Both when you’re choosing and enjoying wine.

Aromas can add to the drinking experience, but they can also indicate a wine you may not want to consume. There are a few smells you’ll want to be mindful of as they are a great indicator of something going wrong.

Acetic Acid

This aroma is one of the most pungent. The presence of too much acetic acid in the wine will give off a vinegar or sauerkraut smell.

An abundance of acetic acid turns wine into vinegar. If you open a bottle and catch a whiff of this tangy acidic smell, there will be no question about it. And trust us, you won’t want to give it a taste test.


As with acetic acid, too much oxygen is bad for wine. The aroma is another way to tell if you miss the other signs of an oxidized wine.

A wine that’s gotten too much oxygen will have sherry-like qualities. The aroma will be overly sweet and nutty, similar to applesauce or a burnt marshmallow.


Brettanomyces (Brett) is a yeast commonly used in alcohol production. When fermented properly, it creates the correct amount of acetic acid. As a result, it gives a weathered leather or rustic quality that can complement many other flavors in wine.

However, when Brettanomyces get out of control, the aroma takes a turn south. Sometimes praised in beer, an overgrowth of Brett can give off some pretty funky smells. These include wet farm animals, a barnyard, a slightly metallic note, or even a band-aid.

Cork Taint

An unwanted chemical reaction occurring within the production process is a more common term. TCA (2,4,6 Trichloroanisole) or cork taint will give your wine a wet newspaper, wet dog, or musty cardboard aroma. This pungent smell is a huge indicator of bad wine and will overtake any fruit fragrance.


The final way to tell if your wine is faulty is to take a sip. We know this probably isn’t where you’ll start if you think a wine may be bad. But in case you don’t notice the other signs, here are a few flavors your wine shouldn’t taste like.

Sharp or Sour

Referring back to acetic acid, this is definitely not what wine should taste like. Tangy, acidic, and vinegar-like are more of what you look for in a pickle, not a glass of wine. Sharper or more sour flavors immediately let you know a wine is bad.

They come from an array of unwanted chemical reactions that have taken place during production, packaging, or after the wine is open.

Overly Sweet or Sherry-like

There are other things that can go wrong in the wine process that can lead to slightly less offensive flavors but are still indicators of a flaw in the wine. Heat damage (think of a bottle sitting in the sun) and over-exposure to oxygen can lead to these flavors appearing.

These flavors will come across as jam, sherry, or roasted sugary fruit. Something about it is vaguely attractive and yet still slightly processed. Proper storage can help to prevent these flavors from developing.

Final Thoughts

There you have it, a few ways to spot a faulty wine before it ruins your dinner plans. The next time you question whether a wine is worth drinking, refer back to this article.

Your friends will think you’re a wine connoisseur. And when you spot a flawed wine, you’ll feel like one too.