When a Bottle Goes Wrong

Every smell in a glass has a cause you can name. Last time that idea sorted aromas into three groups: the grape, the winery and time. A wine fault works the same way. It is a smell or taste with a cause, and once you know the cause, you can usually tell whether you are meeting a flaw or a style someone chose on purpose.

This lesson finishes the tasting unit. You already know how to describe a wine's structure: sweetness, acidity, tannin, alcohol, body and finish. You also know how to write a four-part note. What is left is the question a taster asks before any of that: is this bottle sound? By the end of this chapter you can answer it.

Six faults and what causes them

A fault is a change that hides what the wine should show. That definition matters, because it is about the wine, not about you. A wine you dislike is not faulty. A wine whose fruit has been buried under mold, vinegar or burnt rubber is.

Most faults leave two kinds of mark. One is a smell you can name. The other is subtler: the wine's own fruit goes quiet. So a faulty glass often gives you a warning in two parts. Something is there that should not be, and something is missing that should be there.

Here are six faults in turn. For each one you will hear the cause, the signs, and how sure a taster can be.

Start with cork taint, the fault people mean when they say a wine is corked. The cause is a chemical called TCA, short for trichloroanisole. It forms when molds meet certain chlorine-containing compounds, and those can sit in cork bark, in wooden winery structures, or on processing equipment. Once TCA is in a bottle, it smells musty: damp cardboard, wet dog, an old basement.

The amount it takes is tiny. Trained tasting panels pick up TCA at a few billionths of a gram in a liter of wine, in the range of two to five. People also differ enormously. Some tasters are up to two hundred times more sensitive than others. So if someone at your table says a wine is corked and you smell nothing, you may both be right.

That difference is why cork taint is tricky. At low levels you may smell no mustiness at all. You just find the wine dull, flat and hollow, as if its fruit had been switched off. Many people blame the wine or the winemaker when the real cause is the closure.

How common is it? Sources disagree, so here is the honest range. Older figures had cork taint in somewhere around two to five percent of natural corks. The cork industry's own estimates today run around one percent, after years of better screening. Independent counts of commercial cork problems come in somewhat higher, up to a few percent. Every count agrees that it is far less common than it once was, and that it has not gone away.

Next is oxidation, which means too much air. Oxygen turns some of the wine's alcohol into a compound called acetaldehyde. You can see it before you smell it. A white goes amber or brown, and a red goes brick-orange well before its age explains the color. On the nose you get bruised apple, stale nuts, stewed fruit and something like sherry. The palate tastes flat and a little bitter, with the freshness gone. The air can get in through a dried-out or failing cork, a leaky seal, or careless handling in the cellar.

There is an obvious objection: aren't some wines made this way on purpose? Yes. Oloroso sherry, the vin jaune of France's Jura region, and many orange wines get controlled oxygen as part of the style. The difference is what surrounds the nutty notes. In a deliberate style you find walnut, dried apricot, sometimes a salty edge, and firm acidity holding it all up. Accidental oxidation gives you the nuts and the brown color with nothing behind them, just tired fruit that has lost its life.

Reduction is the opposite problem: too little air. When yeast are stressed, short of nutrients or kept away from oxygen, they can make sulfur compounds. Too much added sulfur can push things the same way. The results smell like a struck match, burnt rubber, cooked cabbage or rotten egg. The palate feels tight and the fruit seems held back.

Here the line between fault and style runs right through the middle. In small amounts, a struck-match or flinty note is something many winemakers aim for in cool-climate Chardonnay and Syrah, because it adds tension and interest. When it slides toward sewer or rotten egg, it is a fault.

Reduction also has a feature the other faults lack: sometimes it goes away. Some of the sulfur smells are volatile enough to drift off once the wine meets air. If a glass smells of matches when first poured, swirl it and give it a few minutes, or pour the bottle into a wider jug or decanter. If the smell fades and fruit comes through, the wine is fine. If it stays, or turns into cabbage and rubber, it isn't.

Volatile acidity is usually called VA. Every wine has a little. It becomes a fault when acetic acid bacteria, or some wild yeasts, get to work with oxygen around. They make two main things. Acetic acid is the acid in vinegar, and it smells like vinegar. Ethyl acetate smells like solvent, varnish or nail-polish remover. On the palate, too much VA gives a sour prickle and a burning sharpness on top of the wine's own acidity.

A small amount can help. A trace of VA can make the aromas seem to jump out of the glass, a quality tasters call lift. Some traditional reds from southern France and Tuscany have long carried a little. The test is whether the vinegar or solvent note takes over. Lift sits underneath the fruit. A fault sits on top of it.

Brettanomyces, almost always shortened to Brett, is a yeast, but not the one that makes the wine. It is a spoilage yeast that can live in oak barrels and thrives where there is little sulfur to stop it. It turns certain natural grape compounds into two smelly chemicals, 4-ethylphenol and 4-ethylguaiacol. Brett smells of barnyard, horse stable, sweaty leather and adhesive bandages. As it grows, it strips the fruit out of the wine and can leave harsh, drying tannin and a metallic finish.

Brett is the most argued-over fault, because a trace of it can read as savory, earthy or rustic. Some tasters accept or even like a little in certain old-school reds. This is also where your lesson on tertiary aromas helps you. Leather and earth can come honestly from age. Brett's version tends to arrive with the medicinal bandage note and with fruit that seems drained rather than matured. If the wine still has its fruit and the leather sits quietly beside it, call it character. If barnyard and bandages are most of what you smell, call it Brett.

Heat damage is sometimes called maderization, after the cooked style of Madeira. It comes from heat in shipping or storage. Leave a case in a hot car, a warehouse or a sunny shop window, and the liquid expands. It can push the cork up and break the seal, which then lets air in as it cools. The wine smells and tastes cooked: baked fruit, prunes, jam, caramelized sugar. It feels dull, with the acidity that gave it energy gone slack.

Heat damage often leaves physical evidence before you pour. Look at the top of the bottle. A cork pushed up above the lip, or a sticky stain of wine around the capsule, suggests the bottle has been hot.

Is it the wine or is it you

Knowing the six faults is one skill. Using that knowledge on a real glass takes judgment, so here are the checks that help.

First, ask whether the smell hides the wine or belongs to it. That is the definition from the top of the lesson. A struck-match note in a vivid Chardonnay with plenty of fruit belongs. A struck-match note so strong you cannot find the fruit doesn't.

Second, ask whether the style explains it. A sherry is meant to be nutty and an orange wine is meant to have some grip and oxidative notes. A two-year-old Pinot noir that smells of sherry has gone wrong, because nothing in how Pinot noir is made should give it that.

Third, compare with a second bottle when you can. Cork taint and heat damage happen to single bottles. Brett, VA or heavy reduction often began in the cellar and may run through the whole batch. If a second bottle of the same wine is clean, the first had a bottle problem. If it smells the same, the wine was made or stored that way.

Fourth, notice what is not a fault. Haze or slight sediment in an unfiltered wine is a choice, not a flaw. So are the tiny clear crystals that sometimes form on a cork or at the bottom of a white wine kept cold. Those are tartrates, crystals of the tartaric acid you met in lesson two, and they are harmless.

Then there is the question of closures. A screwcap cannot carry TCA from cork bark, so it removes the main source of cork taint, though TCA picked up elsewhere in a winery can still turn up. A screwcap also lets in less air than most corks, so oxidation through the closure becomes far less likely. The trade-off is that a tight seal leaves sulfur compounds less chance to escape. Many winemakers watch reduction more closely in wines going under screwcap for that reason. Neither closure is free of faults. Each shifts which faults you are most likely to meet.

At a restaurant, the small ritual when a bottle arrives exists to catch faults. It is not there to ask whether you like the wine. Here is how to use it.

1. Check the label against what you ordered: the producer, the wine's name and the vintage.
2. Look at the cork, but do not sniff it. A cork raised or wet down its side can point to heat, but a cork always smells a bit like cork.
3. Smell the small pour in the glass. If it is clean, take a small sip and notice whether the fruit and finish seem alive.
4. If something is wrong, describe it plainly, for example that you are getting a damp-cardboard smell, and ask the server or sommelier to smell it too.
5. If it is a bottle problem such as cork taint, ask for a second bottle of the same wine. If the whole wine seems off, choose a different one.

A good restaurant will thank you, because a corked bottle is usually something it can return to its supplier. What you cannot send back is a sound wine you simply don't enjoy, which is one more reason to know the difference.

At home, the steps are simpler. Smell first. If it is reduced, give it air. If it is corked, oxidized, cooked or full of vinegar, stop. A faulty wine will not improve, so don't make yourself drink it. Pour the tasting sample into the spittoon or the sink, the way professionals routinely do, and keep the bottle and receipt if you bought it recently. Many shops will replace a faulty bottle.

Now build all of this into your tasting note. The note still has four parts: appearance, nose, palate and conclusion. The soundness check begins at the first sniff, because the nose is where most faults show up first. Your note should record what you found there, and then give its verdict in the conclusion.

Here is a worked example. Say you open a young red and pour a small glass. Appearance: medium ruby, clear. Then the nose, and the first question is whether it is clean. Say yours smells faintly musty, and the cherry you expected seems far away. You swirl and wait a few minutes, and the mustiness stays while the fruit doesn't return. That points to TCA rather than reduction, because reduction often fades with air and cork taint doesn't. So your note reads: nose unclean, musty, damp cardboard, fruit muted. On the palate you would still note structure if you taste at all: medium acidity, light tannin, a short and hollow finish. Then the conclusion: faulty, probable cork taint, not assessed for quality.

That last line is the key. On the quality scale from lesson four, where all four measures make a wine outstanding, a faulty wine scores nothing. You are not saying the wine is bad. You are saying this bottle cannot show you what the wine is. If a second bottle is clean, you write a fresh note and judge it properly.

For a sound wine, the conclusion simply gains one more line: sound. Most bottles you ever open will be. Writing the word anyway keeps the check a habit.

With that, the tasting unit is complete. You can look at a glass and describe it by its structure, its sweetness, acidity, tannin, alcohol, body and finish, rather than by whether you like it. You can sort its aromas into grape, winery and age, judge its quality by balance, length, intensity and complexity, and write it down in four parts. And you can tell, before any of that, whether the bottle in front of you is sound.

Smoke taint in the valley

There is one more fault on the list, and it is the one the Willamette Valley knows from its own vineyards. Smoke taint comes from wildfire smoke drifting over vines while the grapes ripen.

Burning wood releases a family of compounds called volatile phenols. The best known is guaiacol, which smells smoky and is part of why grilled and smoked foods taste the way they do. Others include 4-methylguaiacol, the cresols and syringol. You may notice that guaiacol shares part of its name with 4-ethylguaiacol from Brett. Both belong to the same broad chemical family, which is one reason smoke taint and Brett can both drift toward medicinal smells.

The grapes take these compounds in mostly through the waxy skins of the berries. It happens from the point where the grapes change color, called veraison, through to harvest. Leaves take in only a little.

Then comes the step that makes smoke taint sneaky. Inside the berry, the vine attaches many of these smoky compounds to sugar molecules. Bound to sugar, they no longer evaporate, so they have no smell. A grower can stand in a smoky vineyard, crush a berry, smell it and find nothing much wrong.

The taint shows up later. During fermentation, yeast activity and the wine's acidity break some of those sugar bonds and set the smoky compounds free. Some of the bound forms survive into the bottle and come loose slowly as the wine ages. Others break down in your mouth, where enzymes in saliva do the same work. That is why smoke taint often shows less on the nose than as a flavor once you sip: cold campfire, ash, charcoal, sometimes a medicinal note, and a drying, ashy finish.

Because the smell hides, testing matters. Laboratories measure both the free smoky compounds and the bound ones, guaiacol and 4-methylguaiacol among them. Wineries also make tiny trial fermentations before harvest to see what the fruit will taste like once yeast has done its work.

The valley learned this lesson in September 2020. After Labor Day that year, more than a million acres burned across Oregon, and dense smoke sat over the Willamette Valley for more than a week. Pinot noir was badly placed to cope. Its skins are thin, and red wine is made by soaking juice with skins for days or weeks, which pulls out whatever the skins hold. The skin contact that gives red wine its color and tannin also carried the smoke compounds into the wine.

Effects varied from site to site and winery to winery, so it is fairer to describe the range than to give one verdict on the vintage. Some producers stopped altogether. De Ponte Cellars in the Dundee Hills, for example, cancelled its estate Pinot noir for the year. Many growers left fruit hanging unpicked or filed crop insurance claims. Others found ways to make something from it. They turned red grapes into rosé or white Pinot noir, pressing the juice off the skins quickly so less of the taint came with it. Some used treatments such as carbon fining, or a spinning cone, a machine that separates and removes some compounds at low temperature, to strip some of it out.

For you as a taster, there is a practical point. If you open a valley red from 2020 and find ash or cold campfire on the finish, you have a likely cause. And because bound compounds can loosen over time, the same wine may taste smokier in a few years than it does today.

Practicing at Ricochet

The show's home winery, Ricochet Wine Co. in McMinnville, makes a good place to put this lesson to work, and its own account of how it makes wine connects with faults in a useful way.

Ricochet's motto is "If we don't have to do something, we don't." In practice that means, by Ricochet's account, it adds no sulfur to the grapes as they come in. It encourages native yeast, the yeast that arrives with the fruit, though it does not always use it. With few exceptions, it leaves its wines unfined and unfiltered. Low sulfur does not mean none. Several of its technical sheets note a limited amount added after malolactic conversion.

That matters here because sulfur is one of a winery's main defenses against spoilage yeast like Brett and against bacteria that make VA. A winery working with less of it is choosing to rely on clean cellar work and careful watching instead. Ricochet's 2023 Confluence Rosé shows the trade-off openly. Ricochet stopped its malolactic conversion short to keep its acidity, and so it filtered the wine for stability, one of the exceptions to its usual practice. Filtering removed the organisms that might otherwise have restarted that conversion in the bottle.

Ricochet's sparkling Le Ressort teaches the other half of the lesson, the part about what is not a fault. It is a pétillant naturel, a pet-nat, made from Pinot gris, and Ricochet says it was never sulfured and never disgorged, so slight lees remain in the bottle. A little haze in that glass is the style showing itself, exactly as the maker intended. Treating it as a flaw would be the kind of mistake the fault-or-style check is built to prevent.

Any small winery that buys its grapes rather than growing them faces the smoke question too. Its fruit comes from growers' vineyards, and a smoky September would land on all of them. The tools you just heard about, lab tests and small trial fermentations, are what wineries generally rely on when deciding whether to pick and make a wine at all.

When you visit Ricochet in McMinnville, booked through ricochetwine.com, start each pour with the soundness check before anything else. Smell the 2022 Holmes Gap Pinot noir and the 2023 Pinot blanc first for cleanness, decide they are sound, and only then write your four-part note. Ricochet belongs to a friend of the show, which makes it a fine place to practice the habit. Use the spittoon or bring a designated driver.

That habit has a fresh vintage to work on this year.

The 2026 harvest is finished in the northern part of the valley. On October 22, winemaker Josh Bergström of Bergström Wines reported that the picking was done. His winery's lots had finished their main fermentation and were moving into malolactic conversion. That is the step from lesson two, where sharp malic acid turns into softer lactic acid, and it is where the new wines are sitting now.

Bergström called 2026 one of Oregon's finest cool-climate vintages in decades. That is one producer's early judgment, and critics' verdicts will come once the wines are tasted. The weather he described explains why he is hopeful. No day reached a hundred degrees Fahrenheit, and fewer than ten passed ninety. There were no heat spikes and no rain damage, and the intermittent rain kept soil moisture up without drought stress.

Long, mild weather let the grapes hang on the vine and ripen slowly. By his account, that gave Pinot noir and Chardonnay balanced natural acidity, deep color, firm tannin and vivid aromas. That fits what you heard about the valley's cool climate: slow ripening keeps acid while flavor builds.

The new wines need time, so the season moves to tasting what is already in bottles. The Willamette Valley Wineries Association holds its Harvest Celebration at the Portland Art Museum on November 11, with fifty-four of the region's wineries. Closer to home, Ricochet holds its Fall Social Club Release on Saturday, November 7, from noon to five, and its Indie Wine Mixer, called "A Very Indie Thanksgiving," on November 21 and 22, also noon to five. At any of them, the first sniff of every glass can ask the same question this lesson taught: is it sound?