How do you know if unopened champagne is bad?

Quick Answers

Here are some quick answers to determine if unopened champagne is still good or has gone bad:

  • Check the bottle label for a production or expiration date – champagne generally lasts 3-5 years after the production date if properly stored
  • Inspect the cork and bottle – dried, crumbly, moldy corks or leaking bottles can indicate spoiled champagne
  • Check for sediment – excessive sediment can be a sign of refermentation and off flavors
  • Give the bottle a smell check – spoiled champagnes will have off odors like vinegar, nail polish remover, or rotten eggs
  • Taste a small sample – bad champagnes will have altered flavors like sourness, bitterness, flatness, oxidation, or yeastiness

How to Read the Production Date

One of the first things to check on a bottle of unopened champagne is the production or expiration date printed on the label. This date is typically formatted as a month and year, such as 10/2013 for October 2013.

Champagne producers are not required to put expiration dates on their bottles, but many voluntarily provide this information as a benchmark for peak drinking. The production date refers to when the champagne was bottled after the final fermentation process.

As a general rule of thumb, champagne tends to last:

  • 3-5 years after production date if kept properly stored
  • 5-7 years for vintage or high quality champagne stored optimally
  • 8-10 years or longer for premium vintage champagne aged in ideal conditions

So if you have a bottle with a production date of 10/2013, it should optimally be consumed between 2013-2018. Of course, these are just broad guidelines – the way the champagne was stored is the most important factor.

Ideal Storage Conditions

Champagne needs proper storage to maximize its shelf life. Ideal conditions include:

  • Constant cool temperature around 55°F (12°C)
  • High humidity around 60-70%
  • Kept away from light sources
  • Stored upright to keep cork moist
  • Vibration free storage

Champagne stored for long periods in less than ideal conditions is more prone to premature aging and quality deterioration. Signs like leaking corks, dull or faded labels, and loose foil capsules can hint that the champagne may be past its prime.

Inspecting the Cork and Bottle

Along with checking the production date, closely inspect the actual bottle and cork for any defects or damage.

Look for these warning signs of a potentially bad champagne:

  • Dried out, cracked, or crumbly cork – Indicates old age, poor sealing, and possible oxidation
  • Mold or mildew on cork – Usually caused by improper storage and excess humidity
  • Deposits or seepage around cork – Leakage can mean improper cork seal and bacteria contamination
  • Cloudy or discolored cork – Could be oxidation or refermentation buildup
  • Watery stains or rust on capsule/cage – Sign of seepage past the cork from internal pressure
  • Bulging or bulging cork – Pressure buildup from carbon dioxide or refermentation
  • Sediment in the bottle – Usually harmless yeast deposits but can indicate refermentation
  • Yellow or brown discoloration – Normal aging but can also signal oxidation

While things like bottle stains or minor sediment may not automatically mean the champagne is bad, they do indicate it is likely past peak quality and aging.

How Cork Taint Happens

One of the most notorious faults in bad champagne is cork taint. This happens when the cork becomes contaminated with the chemical compound TCA (2,4,6-trichloroanisole).

Cork taint causes a musty, moldy smell and off flavors. Because TCA seals in the cork, it can ruin champagne even if the bottle looks pristine. Estimates suggest 2-7% of wine corks are tainted with some level of TCA.

So don’t rely solely on the appearance of the cork – always sniff the cork specifically looking for any “wet cardboard” odors. Bad corks should be immediately apparent from the foul smell.

Checking for Excess Sediment

Sediment consisting of yeast remnants and tannins is naturally present in champagne and forms harmless deposits. But excess sedimentation combined with cork or bottle defects can indicate unwanted refermentation and stability issues.

Look for these sediment warning signs:

  • Thick layer >3mm at bottle bottom
  • Cloudy appearance throughout liquid
  • Particles suspended when bottle moved

While a small amount of sediment is normal, excessive lees can give the champagne a yeasty flavor. Sediment can also be stirred up if the bottle was improperly stored on its side instead of upright.

How Refermentation Happens

Refermentation is when dormant yeast wakes up in the bottle and starts consuming residual sugar, causing re-fermentation. This produces carbon dioxide and sediments. The wine becomes cloudy, fizzy, and pushes against the cork.

Signs of refermentation in spoiled champagne:

  • Overpowering yeasty flavors
  • Frothy or foamy appearance
  • Gushing bubbles or pressure when opened
  • New layers of sediment

While not toxic, severely re-fermented champagne is considered flawed. However, refermentation in vintage champagnes can sometimes improve flavor over years of aging.

Checking the Smell for Off Odors

Your nose is one of the best tools for assessing whether an unopened bottle of champagne has gone bad. Give the bottle a good sniff near the bottom seam and cork junction for any odd aromas.

Common off smells in bad champagne include:

  • Vinegar – Acetic bacteria turned alcohol to acetic acid
  • Nail polish remover – Oxidation caused ethyl acetate compounds
  • Wet cardboard – Cork taint from TCA contamination
  • Rotten eggs – Hydrogen sulfide gas byproduct
  • Old apples – Oxidative aging into acetaldehyde compounds
  • Barnyard – Contamination by Brettanomyces yeast

The strongest indicator is often the smell. A bad champagne will immediately assault your nose with overtly unpleasant aromas. Trust your senses – if it smells off, it likely is.

When To Open the Bottle

You don’t need to prematurely open the bottle for this sniff test. But if the champagne already shows multiple warning signs – such as a leaky cork, odd sediment, and production date over 5 years old – go ahead and unseal it to get a better whiff.

Opening a spoiled bottle can release a sudden buildup of pressure. So point the cork away from people and be prepared to contain spills.

Tasting for Flavor Defects

The ultimate test is to actually sample the champagne. This should provide clear taste evidence if the champagne has become unpalatable.

Look out for these common flavor flaws in bad champagne:

  • Sourness or vinegar flavor – Acetic spoilage
  • Bitterness – Oxidation or light damage
  • Flat or lacking bubbles – CO2 loss
  • Madeirized flavor – Oxidative aging
  • Sherry-like flavors – Oxidation
  • Yeasty or sulfury tastes – Refermentation

Even small amounts of contamination or oxidation can strip champagne of its classic taste and aromas. You’re looking for clean, bright fruit, brioche, minerality – not anything muddled, stale, or acidic.

Serving Tips

When tasting older champagne, be sure to sample it properly at its ideal drinking temperature of 45-50°F (8-10°C).

Evaluate the champagne in a basic tasting glass against a white background. Assess its appearance, aromas, and flavor nuances.

Take notes on the taste now, versus if you retaste it 30 minutes later after more air contact. Often times, flaws become more apparent upon exposure to oxygen.

If the champagne tastes flat, bitter, or vinegary right off the bat, it is well past its prime. But heat and air can also quickly degrade champagne, so limit sampling to small servings.

Signs of Aging vs Spoilage

As champagne gets older, it takes on darker golden hues and more intense toasted flavors that can seem like flaws at first. Here’s how to distinguish normal aging from true spoilage:

Aging Characteristics Spoilage Warning Signs
Deep golden color Cloudy appearance
Noticeable sediment Excessive sediment
More oxidative aromas like honey, caramel, almonds Off odors like vinegar, chemicals, rotten eggs
Richer, nuttier, sherry-like flavors Bitterness, flat or sour taste

While an older champagne won’t have the same vivacity as when first released, it should still retain complexity without defects. Signs like irreversible clouding, chunky deposits, and harsh flavours indicate spoilage rather than graceful maturation.

How Long Can Champagne Last?

Under perfect cellar conditions, champagne has impressive longevity. Vintage and premium cuvées produced in the best years can potentially stay enjoyable for decades. For example, a well-stored 1996 Dom Pérignon can still taste fantastic today.

But such longevity requires optimal storage. The vast majority of champagne is consumed within 5 years of production. And anything over 10 years old should be meticulously inspected before opening.

While champagne is bottled under high pressure to allow it to age, it is still highly perishable compared to spirits or canned goods. The cork seal and complex chemistry make it vulnerable to oxidative damage and microbiological faults.

So champagne doesn’t have an indefinite shelf life. Use discretion when deciding if an unopened bottle is past its prime, even if stored properly. Signs of seepage, off smells, or bitter/flat flavors are the ultimate test.

How to Salvage Cooked Champagne

Heat damage is champagne’s worst enemy. Excessive warmth can speed aging and cause a dull, Madeirized flavor.

A champagne that has been improperly stored in hot conditions or allowed to get too warm is considered “cooked.”

Signs of heat damage include:

  • Accelerated darkening
  • Flatness with loss of effervescence
  • Madeira-like brown flavors
  • General imbalance and tiredness

Unfortunately, cooked champagne is not safe to consume and cannot be revived. But it can be salvaged into:

  • Champagne vinegar – Allow fermentation into vinegar
  • Champagne jelly – Boil with sugar into preserve
  • Champagne cocktail mixer – Blend with other alcohols and juices

This prevents waste while pivoting the champagne into a new creation where heat damage won’t be as apparent.

How to Prevent Heat Damage

To avoid cooking champagne in the first place:

  • Store at cool cellar temperature below 60°F (15°C)
  • Transport chilled and avoid leaving bottles in hot cars
  • Keep champagne on ice or refrigerated at events
  • Return unconsumed bottles to the fridge
  • Watch for warm microclimates like near appliances

Champagne is best served chilled at 45°F (8°C). Just brief exposure to high temperatures can irreversibly ruin the delicate flavor.


Determining ageability based on production dates is just a starting guideline. The ultimate test is the condition of the cork, sediment levels, aroma, and taste.

With premium storage conditions, champagne can potentially last and even improve from aging over a decade. But compromised storage accelerates decline.

Look for warning signs like leakiness, off smells, bitterness, excessive bubbles, and lack of complexity. These indicate oxidation, refermentation, and microbiological faults which spoiled the champagne.

While not harmful, bad champagne won’t provide an enjoyable experience. Always inspect older bottles carefully and taste before serving.

With vigilance to storage and warning signs, you can better judge a champagne’s drinkability after years sealed away in the cellar.

Leave a Comment