Recently I opened a 10 year old Burgundy that I had heard great things about. I was so excited to try it. I poured a glass, gave it a nice swirl, stuck my nose in it, and took a deep inhale. Then I pulled back choking because all I could smell was vinegar. I decided to try a sip, just in case something strange was happening with my sense of smell. It tasted like old fruit. Worst. Let down. Ever.

Why was my wine so bad? It had been oxidized. Oxidation is one of the most common wine faults, along with cork taint, cooking, and accidental secondary fermentation. Let’s discuss each so you know how to tell what is causing a problem with your wine.


Oxidation occurs when wine is exposed to air. It’s not always a bad thing- as wines age they are exposed to small amounts of air through the cork, which helps their flavors develop. However, when a wine is overexposed, the flavors become muted and the wine can begin to taste like vinegar. White wine becomes darker, while red wine gets lighter and more brown.

Two common causes of oxidation are poor storage and being left open too long. Wines with real cork need to be stored on their sides to keep the cork moist. Cork shrinks when it dries out, allowing more oxygen into the bottle. This accelerates the aging process, and if you don’t catch it in time the wine will spoil.

Wine also oxidizes after you open it. As soon as the cork comes out, oxygen enters the bottle and the process begins. If you don’t finish the bottle, it’s important to use a wine preserver to remove as much oxygen as possible. If it’s going to take more than a few days to finish the bottle, consider a Private Preserve, which displaces the oxygen with inert gas, or a Coravin.

Cork Taint

Cork taint occurs when musty aroma compounds contaminate wine, most commonly by 2,4,6-trichloroanisole, or TCA. This can only occur with real corks, not synthetic or twist cap, because it is caused by the exposure of cork to chlorine. TCA occurs in about 2-3% of all wine with real corks, but many people use “corked” as a catchall term for when a wine is bad.

The hallmark of cork taint is the smell. Think damp, dank, wet cardboard. It’s one of those things you might think you smell from time to time (that’s probably mushroom or earth), but when you really smell it, you really smell it. You will always know when you smell a wine with cork taint and there is nothing you can do to fix it.


Cooked wine can be a little hard to tell because some of the flavors associated with it can be seen in wine that’s perfectly good. Cooked wine has had sustained heat exposure, which essentially cooks the wine in the bottle. Cooking can occur at any point, from storage to shipping to going from the store to your home on a hot day.

Jammy or cooked fruit flavors are one tell of cooked wine, but there are other ways to tell the wine was cooked. The cork may also be pushed out of the bottle slightly (always proceed with caution when you see this- you never know how it will taste or smell). The flavors will be jammy, or nutty in the case of white wine, but in a bad way. It may also exhibit some discoloration as in the case with oxidation.

Accidental Secondary Fermentation

Accidental secondary fermentation occurs when residual sugar is bottled with the wine and it goes through secondary fermentation in the bottle when it’s not supposed to. It occurs most often in young red wines.

How do you know a wine has been through accidental secondary fermentation? First, it might hiss slightly when you open it, and there will be little tiny bubbles in it, but you’re not drinking a sparkling wine. It might even taste a bit fizzy. It usually doesn’t have strange flavors, but the flavors can be muted.

When you do come across a fault, put the down and don’t drink anymore- it’s not worth it. If it’s that way straight off the shelf, take it back to the store you bought it from and ask to exchange it. Don’t pour it out, just stick the cork back in and drive it back. Most places understand that faults happen and will happily switch out the bottle for you. If you’ve had the bottle for awhile and the wine is oxidized or cooked, think back over how you’ve stored it and whether it’s been overheated.

I know how frustrating it is when you have a wine you’re excited to drink and there’s a problem with it, but don’t despair. While wine faults do happen, there are many, many great bottles out there with no problems at all.