Wine faults

Today I’d like to offer a brief overview of some of the faults or taints associated with wines. These are the bane of every wine lover’s existence… you have cellared a treasured bottle for 15 years, you have the perfect occasion to open it and enjoy it in all of its perfectly matured glory, you build it up to your guests and talk about how fantastic the pairing is going to be, and then you pop the cork! The wine smells like molded wet cardboard and soggy dog…. oh no!!! You have been foiled by the dreaded cork taint and now you scramble to find a replacement bottle that will still allow the occasion to continue. It’s a devastating moment and it happens all too frequently in my opinion. I personally have had it happen at birthday celebrations, on my engagement night, and at multiple professional dinners. What other industry tolerates 2-5% of their product to be irreversibly flawed?! And what customers tolerate that and continue to buy the product?? Apparently wine consumers, including myself…. This will be a brief overview of a few common flaws, just to allow you to recognize or at least realize that these things exist because you will certainly never recognize a flaw if you don’t even know it could be there.

For me, wine fault recognition began with cork taint. It is named such because the fault is actually with the cork, not the wine. The compound that causes the flaw is 2,4,6 trichloroanisole (TCA for short). TCA is generally produced during the cork sterilization process. Bleach (chlorine) is used to wash the corks and if there is a certain strain of fungus that is exposed to the chlorination, TCA is produced. Now technically speaking cork is not the only source of “cork taint”. Barrels, tanks, hoses, or other products in the winery can be the cause. However, for simplicity, we will just blame the corks for now. First, let me allay your fears. TCA is totally harmless to you. So if you have consumed corked bottles, there are no negative effects to you. Phew… I suspect many of you have consumed corked bottles (including myself). Interestingly, the taste of the wine is largely unaffected by the flaw. It simply destroys the aromas. Instead of beautiful cassis, menthol, oak spice, and tobacco in your cabernet you get wet dog and moldy basement. Instead of bright cherry and raspberry, clove, iron, and violet in your pinot noir you get wet cardboard and newspaper. TCA is recognizable in absolutely minuscule concentrations. The average person can smell it at 6-10 parts per trillion. Yes that is trillion with a T. Sure, this varies, but still everyone can recognize in unbelievably tiny amounts. Estimates on the incidence of TCA taint varies widely. The cork industry generally quotes 0.5-1%. Wineries often quote 5-8%. A blind tasting of wines at a major professional publication about a decade ago found that 7% of the wines were flawed with TCA. My own personal experience is probably around 3-5%. The bottom line is, it is common and if you drink wines that are sealed with cork, you will come across it. So, be alert and when you smell a wine that is supposed to have lots of fruit notes, and they aren’t there, look for the mold note. A tip that I have learned is to put the wine down and leave it alone for 3-4 minutes. Your sense of smell rapidly habituates and the smell can “disappear” in only 2-3 sniffs. If you think you sense it on sniff one, set the wine down, clear your nose for a few minutes, then come back to it. Give the wine a vigorous swirl and take only 1-2 sniffs. You will pick it up immediately. If you encounter this at a restaurant, send the bottle back. Tell your waiter the bottle is corked and you will get a new bottle. Restaurants universally take back corked bottles. Some restaurants will challenge you (this has happened to me on at least 3 occasions) and have their own wine professional assess the bottle, but don’t worry. You are probably right (I am 3 for 3 when I’ve been challenged). Some shops will take back corked wines, but not all. Its worth a call or a drop in, especially if it was a spendy bottle.

Now let’s move on to a controversial flaw that is more common than TCA. Brettanomyces or brett for short is probably the most common wine flaw. Brettanomyces is a yeast strain that can get into wines and cause off flavors of various types. Brett is universal. It is everywhere. It is very common in wines, most commonly red wines. It is also common in beers and often times is used intentionally in beers. The thing that is very interesting about brett, is depending on the person and the wine, sometimes it is actually thought to be a nice addition in small doses. Some incredibly famous wines consistently have flavors that are due to brett (Haut Brion for example). So it is a flaw that is sometimes not really considered a flaw. The flavors produced by brett develop in wine after the primary fermentation. It is more common in red wines, because lower pH’s suppress brett. Thus, white wines that are more acidic generally suppress the activity of the yeast. The amount of “off” flavors that are produced depends on the concentration of brett in the wine and on the amount of sugar left for it to eat. Brett can use non fermentable sugars or any small amount of residual sugar left. Thus, it tends to be more noticeable in higher alcohol red wines. These wines often have a little more residual sugar because the regular saccharomyces yeasts can’t quite finish the fermentation as you approach 15-16% alcohol. Then brett can pounce on these left overs. The aromas of brett are wide and dependent on the concentration. At low concentrations, brett generally just reduces the fruit flavors of the wine because there are esterases which break down the esters that often provide the fruity smells and flavors. If brett continues to work the flavors start to morph into spicy, medicinal notes. Think antiseptic notes here. Finally, the most classic flavors of brett develop and these are barnyard, sweaty horse, manure, Band-Aid, and leather. You may note that some of these smells are often used in a positive way in describing red wines and this is quite true. I for one enjoy a little bit of barnyard or leather, though as a background note and not the primary. Thus the issue with brett. Sometimes it can actually be interesting in the wine! So, figure out if you like it and if not, try to avoid it. Again, you should be able to send back a wine for being flawed by brett, so if you note it in overwhelming quantities, send it back!

Ok, last, but not least I’ll mention oxidation. This is another flaw that is sometimes not a flaw. Certain wines are made with intentional oxidation. Madeira, Sherry, and Vin Jaune from the Jura are a few famous examples. Oxidation is exactly what it sounds like, damage caused by oxygen. The whole reason wine is sealed (cork, screw cap, etc) is to prevent oxygen from entering the bottle! At least in significant amounts. Oxidation is inexorable. If given enough time, oxygen will affect and change all wines. Sometimes that may take 150 years, but it will happen. This is normal. It is not normal, however to have a wine that is oxidized early in its life. The most notable region that has had an issue with oxidation recently is Burgundy. White Burgundy has been struggling with “premature oxidation” for the last 20-25 years. White wines that should taste vibrant with lemon peel and floral notes, stone fruits, and minerality were suddenly tasting like nutty, caramel creams. This again, is a normal occurrence if it is 35 years old, but not 4 years old! Oxidation is more commonly noted in whites, but can definitely be present in reds as well. Essentially this is either an error in wine making if too much oxygen contact is given while the wine is being made, or an inappropriate seal of the closure device. In white wines, oxidation can be recognized often visually. Oxidation causes wines to turn brown. Think of an apple exposed to the air and the browning that occurs. The same thing happens to wine. So when you pour a 3 year old Meursault, it should be pale straw or maybe light golden color. If you notice that the wine is a dark gold or certainly light amber color, it is likely oxidized. The nose here then gives you minimal fruit with nutty, spicy flavors, and sometimes some bruised apple/pear notes. The normal vibrancy and fruit is missing. I have sadly experienced this multiple times recently with White Burgundy… including some Corton-Charlemagne that I was very excited about… Oxidation however is not limited to Burgundy so watch carefully for it! Again, some wines are made intentionally oxidized to a certain degree. You have to decide if you like these wines, and if not, don’t buy them. I do think they can be useful to learn a bit about oxidation in wine. Try a traditional white Rioja for example and you will experience some oxidative flavors. These wines are made to employ those flavors, however sauvignon blanc from New Zealand, Condrieu, and chardonnay from Burgundy are not made to show off oxidation and in these wines it is definitely a flaw.

Other common wine flaws include volatile acidity (VA) and reduction or volatile sulphur compounds. There are multiple others that can occur and often can be environmental in nature (smoke taint in California due to the 2017 fires, etc). We will come back to these at a later date. If you can recognize TCA, brett, and oxidized wine you are doing better than the vast majority of wine consumers! There is a helpful smell kit produced by Le Nez du Vin that has 12 common wine flaws and help you recognize them. My advice, if you smell something that seems odd in your wine, ask someone who has more experience to smell it and see if they can tell you what it is that you are smelling. Until next time, I hope that none of us encounter these faults, but if you do at least you will recognize them!

J. Newman, CSW


One thought on “Wine faults

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s