Wine Defects

By / Magazine / July 6th, 2010 / 2

Tasting Note:
Appearance: Tending towards amber/tawny; slightly hazy
Nose: Fetid, pungent, most unpleasant; onion, garlic, rotten egg, band-aid; hurl-inducing
Taste: Kill me. Now.

It’s pretty unlikely, given the advances in winemaking technology, and our understanding of bacteriological bugbears and how to operate hygienic facilities, that you’ll run into a wine with this caliber of malodorous pong and palate-traumatizing yuckiness. But you will, as sure as Malbec will dominate the vinous landscape for at least another month (maybe two), run into the occasional bottle that over-delivers in badness. We’re not talking about those that are simply bland, lackluster and void of joie de vivre (though I personally consider these to be defective), but ones that are actually flawed, defective and thoroughly noxious.

Wine, as I’m sure learned Tidings readers know, is a living substance; a biological being subject to the slings and arrows of outrageous fortune should something go amiss in the vineyard, the winery or even in the bottle. Fermentation itself involves a vigorous tango between yeast and sugar. Much molecular energy is expended in this consummation, and numerous offspring are produced. Some good (alcohol, esters, bubbles, profit for the winery, etc.); some not. And even if the whole act comes off with sparks flying and participants relaxing with a cigarette afterwards, the perils do not end here. In fact, one of the most common wine defects has nothing to do with winemaking at all. To wit, the heartbreak of 2-4-6 Trichloroanisol (TCA, for short).

TCA, or “cork taint,” is the vinous version of “when bad things happen to good people.” As a winemaker, you’ve done everything right. Meticulous fruit selection, hand sorting berries and traditional fermentation; you’ve even, much to the horror of your cohorts, advisors and accountants, eschewed using roto-fermenters, reverse osmosis machines, oak chips, judicious lashings of Mega Red and Mega Purple, and you’ve avoided mega alcohol. Careful aging, fining, racking, and, to really thumb your nose at comvin sense, no filtration. It’s bloody perfect. Imagine, then, the utter, borderline-suicidal rage you’d experience at seeing your masterpiece rendered bilge water courtesy of a hunk of infected tree. Allow me to elaborate.

Cork is tree bark. The inner bark of the cork oak, to be exact. In the process of bleaching cork in a strong chlorine solution to prep it as bottle stopper material, a reaction can occur between chlorine, cork contaminated with TCA, and mould spores. When infected cork is introduced to wine, the reaction is not convivial. The wine takes on a dank, musty, old book/damp basement aroma. What’s particularly insidious about cork taint is that it strikes in various intensities. Sometimes it’s dead obvious. Other times it takes a glass or two (or three) before you say, “WTF?” A corked wine can’t be “uncorked.” It’s a goner. A beautiful wine. Alas, cootie cork. Dinner is ruined. (The world of wine is rather devoid of haiku.)

Luckily, there are alternatives to tree bark. There are those plastic things that act like cork but aren’t cork (the newer generation of which are a far cry from the hernia-inducing originals, but are still sometimes accused of leaching flavour out of wines and encouraging premature oxidation). And there are screw-caps. Long associated with rotgut rouge and the like, screw-caps are now legit closures for top-quality juice, thanks largely to the Kiwis. However, as with many things in life, the elimination of one problem sometimes begets another.

Sulphur is used throughout the winemaking process as a preservative and antioxidant. Sulphites are typically added to wines prior to bottling to preserve freshness, particularly in white wines. Screw-cap closures tend to trap sulphur to a greater extent than cork, and winemakers opting for screw-caps need to be judicious with the addition of this stuff. That burnt match, nose-tingling (and ultimately sneeze-inducing, if you are as sensitive to the stuff as I am) sensation is a sure sign of an overly sulphited wine. Luckily, it tends to blow off with time, so go get a snack, file your tax return or do the laundry. By the time you work up a thirst, the wine should be fine.

Some sulphur problems, however, can be particularly nasty. The general term “reductive aromas” refers to the presence of volatile sulphide compounds in wines. These are formed by the reduction (hence the term) of elemental sulphur, which creates hydrogen sulphide, disulphides and the dreaded mercaptans. Hydrogen sulphide smells not unlike rotten egg. It’s formed during fermentation, and typically dissipates prior to bottling. If it doesn’t, things get bad. Really bad. You won’t often encounter this nasty stuff in commercially made wine, thanks to the fact that it can be successfully removed during the winemaking process. If it isn’t, there’s always the chance that it will morph into the Mother of All Defects: namely, mercaptan (“mercs” in vino geek-speak).

If hydrogen sulphide is bad, full-blown mercaptan is like Dante’s Ninth Circle of vinous hell. Garlic, onion, sweat, skunk, burnt rubber, you name it. It’s all terminal and there is no cure. Again, you will rarely, if ever, have to confront this mythic stinkoid in the wild. However, you are very likely to encounter another odiferous and rather controversial “defect.” This being Brettanomyces, or “brett,” for short.

Brett is a naturally occurring airborne yeast strain (the same yeast that results in the “spontaneous” fermentation of Belgian lambic beers). In small doses it can add complexity to red wines (I’ve rarely encountered it in white). Too much results in band-aid, barnyard, burnt rubber, and horse sweat notes (yum). Your personal accept-a-brett level will vary, depending on your appreciation of wines with a certain degree of funk. To many New World wine judges, brett in any discernable amount is seen as a flaw. Even some Old World types who ought to know better get sucked in.

A while back a member of the British whine press went all screwball over what she detected as “burnt rubber” notes in South African wines (see Tidings October 2009, “Thunderclap Intensity”). It threw the whole industry into a complete freakout. When I heard this I came to a couple conclusions: some members of the press perhaps don’t know as much as they ought to, and many winemakers hang too much importance on the press. It’s brett, lady; get with the program. South African numbers are famous (or infamous) for it. Personally, I actually like a wee shot of brett. I once tasted a Pinotage made in British Columbia that was 100 per cent brett-free. I couldn’t help but feel something was missing.

These are just a few of the uninvited aromatic and flavour spoilers that occasionally show up to wreck the wine-tasting party. There are a myriad of others that belong to the same despoiling lot.

Maderization and oxidation are the Hekyll and Jekyll of wines that have seen better days — typically the result of multiple re-giftings, or the misled belief that wine, like Strontium 90, lasts forever. Baked or stewed aromas in maderized wines, and nutty, sherry-like aromas in oxidized ones are telltale tip-offs. Volatile acidity (VA) wears numerous disguises; vinegar, nail polish remover and other harder to pin down “off” aromas. Butyric acid (rancid butter), lactic acid (cheese), geranium (ascorbic acid-related), pyrazine (aka “ladybug taint” — a defect attributed to the chemical secreted when ladybugs get gooshed up and fermented — remember the 2001 harvest in Ontario?) and overextended sur-lie time (pungent aromas) are other common culprits.

The good news is that most of these are caught during the production process and can be corrected. Even cork taint seems to be less of an issue these days. Whether it’s because corks or getting better or because more wines are sealed with alternative closures is a moot point. Unless, of course, you happen to be a cork. In which case you might want to dust off that resume as your future in the wine industry may be somewhat uncertain.


Tod Stewart is the contributing editor at Quench. He's an award-winning Toronto-based wine/spirits/food/travel/lifestyle writer with over 35 years industry experience. He has contributed to newspapers, periodicals, and trade publications and has acted as a consultant to the hospitality industry. No matter what the subject matter, he aims to write an entertaining read. His book, 'Where The Spirits Moved Me' is now available on Amazon and Apple.

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