Common Wine Faults: A Brief Overview

Imagine you’re out having a date night with your significant other. You order a bottle of wine, and the sommelier returns to your table with the bottle, unopened. She whips out her wine key, opens the bottle with quickness and ease, pours you a small taste, and offers you the cork. What’s the purpose of this ritual?

The sommelier is offering you the chance to examine your wine and the cork for flaws, not to see whether or not you like the wine you ordered.

You pick up the glass and swirl the scanty bit of wine around. You stick your nose all the way into the glass and breathe in deeply. If the wine is perfectly aged and ready to drink, the bouquet should be intense and pleasant, without any “off” aromas. This is the ideal situation.

Sometimes you might experience an aroma that makes you wonder if there’s something wrong with your wine. Maybe the wine doesn’t smell like anything at all. You don’t want to embarrass yourself or insult the somm by suggesting the wine is flawed, so you tell her it’s acceptable. She pours two full glasses. You try to tell yourself the wine is fine, and go on with your dinner. You leave feeling bad because you just paid 3x retail for a bottle of wine that you didn’t enjoy.

My first bit of advice for the person who is questioning the wine he just ordered is to always trust your gut. If it smells bad, there is probably something wrong with it, and you should politely ask the somm to inspect it.

In this article I will go over some potential causes of off aromas in wine – what they are, how they manifest, and how they present themselves.

  1. TCA, or Cork Taint – This is the chemical compound that causes wine to become “corked” or “corky”. No, it has nothing to do with the bits of cork that might be floating around in your wine. How TCA gets into wine is a long, complicated topic, subject to much controversy and many opinions. Instead of boring you with the details, I’ll get right to the meat. TCA can cause a range of aromas in wine, most commonly described as “wet cardboard” or “damp basement”. TCA is believed to occur in 10% or more of commercial wines. If your wine smells like a pile of wet clothes forgotten in the wash for too long, it’s probably infected with TCA. Like most things, there is a range of TCA that can be present in your wine. In small quantities, it may simply rob your wine of fruit aromas and make it taste subdued. Sometimes the wine may seem “closed”, having no aroma at all, and will taste flat and insipid. There is no cure for TCA, so if you believe your wine is corked, politely ask the somm for his or her opinion.
  2. Reduced wine – Some winemakers make their wine utilizing methods that limit the wine’s exposure to oxygen, to preserve freshness and high-toned fruit aromas. They age the wine in steel or other non-air permeable vats instead of wood. They use inert gasses during racking to reduce the wine’s exposure to oxygen. This is called “reductive winemaking”. Reductive winemaking is gaining popularity, especially amongst natural winemakers because they don’t add as much SO2 (a chemical antioxidant) to their wines. Wines made in a reductive manner are called “reduced”.
    Reduced wines sometimes produce off aromas when they are first opened, but it doesn’t always mean the wine is bad. Reduced aromas are usually sulfurous in nature, and are often described as smelling like a struck match, cabbage, eggs, or smoke. If you open a young wine and initially it smells a bit sulfurous, give it a long and vigorous swirl or a light decanting, and it should sort itself out. In extreme cases, the sulfurous aromas don’t go away, and the wine is considered flawed.
  3. Oxidation – Most wine lovers know that high end Burgundy and Bordeaux can age for decades. The aging occurs because tiny amounts of oxygen are let into the wine through the air-permeable cork over time. Bottle aging softens the wine and gives it complexity when done in a slow, controlled manner. If the wine is stored in an environment without temperature or humidity control, the wine can oxidize because too much oxygen gets into the bottle as the wine inside expands and contracts with the temperature fluctuations, or because the cork has dried out.
    Oxidation is more apparent in white wines than red, and red wines are less sensitive to oxygen. If your bottle had seepage around the cork before you opened it, or if the cork was dry and crumbly, chances are the wine is damaged from improper storage and is flawed. You can confirm this by observing and tasting the wine – it will appear brownish in color and taste metallic.
    Some wines are produced in an “oxidative” style, and are not considered flawed or oxidized, such as sherry and vin jaune. This type of oxidation happens in a slow and controlled manner; it’s a stylistic choice. These wines will taste nutty and savory instead of harsh and metallic. They are some of the rarest, most delicious, and food-friendly wines in the world.
  4. Excessive SO2 – SO2/Sulfur Dioxide/Sulfite is a chemical compound that is often added to wine to protect it from microbal growth and oxidation. It may also occur in wine because of elemental sulfur sprayed in the vineyard to prevent the growth of mold on grapes during a particularly damp growing season, and as a byproduct of the yeast converting sugar to alcohol during fermentation. In small amounts, SO2 is undetectable to most people. In higher amounts, it becomes a sensory flaw. It causes the wine to smell of burnt matches or eggs, and can taste harsh or bitter. Well-made wines should not have excessive amounts of SO2. It’s usually the lower-quality commercial wines that suffer from this. We like to avoid wines high in SO2 as a general rule, as it’s implicated as a cause of hangovers and is generally nasty stuff.
  5. Volatile Acidity – Commonly referred to simply as “VA”, it’s caused by acetic acid, the compound that makes vinegar, well, vinegar-y. VA is sometimes a byproduct of fermentation, or caused by spoilage bacteria (such as acetobacter). A small amount of VA is not necessarily considered a flaw in wine, and is sometimes just part of the je ne sais quoi – it usually blows off with a bit of aeration. Too much VA causes a wine to smell irreversibly like vinegar, and is considered a flaw.
  6. Brettanomyces, or Brett – Brett is a genus of yeast that can create a range of aromas in wine. It’s sometimes, but not always, considered a spoilage yeast and creates sensory flaws. Brett can infect entire wineries, which is why some estates have brett in most, if not all, of their wines. It’s notoriously hard to get rid of, and some people think the only way to be sure is by burning the whole place down.
    Some of the aromas created by brettanomyces include cloves, spice, horse blanket, manure, barnyard, band-aids, and rancidity. In small amounts, brett can increase the complexity and character of a wine. Too much, and it’s almost always considered a flaw. Some people are very sensitive to brett and have a negative reaction, regardless of the amount. I have a friend that, at a Loire Valley tasting, thought all of the bretty wines smelled like “corpses”. She is one of those people.

There are many other flaws that one can find in a wine, but these are the most common and, in my opinion, the most offensive. Reading about these flaws is not necessarily going to teach you how to detect them; the only way to really learn is by drinking a lot of wine and paying close attention. I once thought a corked wine smelled like apple peels, and figured it was the way the wine was supposed to be – we drank the whole bottle. I had the same wine later on and realized that it was totally different. It took me years to recognize that what I experienced was TCA, and only after I’d smelled it about a dozen times.

Do you have any tips or tricks for detecting flawed wine? Let us know in the comments.

Sulfites in Wine, Explained


“Contains Sulfites”. What’s the deal? Most people have heard of sulfites in wine, but not many know what this actually means. This article will give you my point of view, a basic understanding of the term, and why sulfites are added to wine (or not).

First off, “sulfites” are commonly referred to as “SO2” or “sulfur dioxide”. SO2 is a chemical compound composed of sulfur and oxygen. It was first used by the Romans in winemaking, when they discovered that burning sulfur candles inside of winemaking vessels (while not in use) kept them fresh and free of vinegar smells.

The basic principle is that SO2 acts as an antioxidant (a safeguard against premature oxidation), as well as an antiseptic and anti-microbal agent. It basically keeps the wine fresh and free of spoilage organisms, although it doesn’t completely prevent these things. It also has a different effect on wine based on the wine’s pH level. The more acidic (lower pH) a wine is, the less SO2 is required to keep the wine fresh. When the wine is lower in acid and higher in pH, more SO2 is required to have the same effect. White wines tend to need higher levels of SO2 because they oxidize easily, while red wines require less as the tannins and other compounds that occur naturally on the skins of grapes act as an antioxidant and antiseptic. The graph below gives you a very basic explanation of the amount of SO2 commonly recommended for amateur winemakers based on the type of wine they are making.


SO2 is commonly added to wine in various stages of the vinification (winemaking) process, in the form of potassium metabisulfite powder or liquid. A dose is sometimes added when the grapes are initially crushed (usually when a lab-created yeast is going to be used for fermentation – to stun any unwanted, wild yeasts or bacteria on the grapes), when malolactic fermentation is complete (malolactic bacteria are very sensitive to SO2), when the wine is being racked (transferred from one vessel to another, to prevent oxidation and spoilage organism growth), while it’s aging in a barrel (to maintain “proper” levels, since over time the “free” SO2 becomes “bound” and ineffective), and when it’s bottled (to prevent oxidation and microbal growth during the transfer to bottle). Not all winemakers add SO2 at all of these stages, and some don’t add any at all. The amount and frequency of SO2 additions is up to the winemaker and there is a lot of controversy regarding the “right” amount to add to a wine.

Some natural winemakers will avoid adding any SO2 at all to their wines, in the name of natural winemaking. These wines tend to oxidize more quickly and have a shorter shelf life (and although I’m sure someone out there disagrees, this is the general consensus). Wines with no SO2 added are also more prone to spoilage during shipping, and when temperatures rise above 60F (warmer temperatures are favorable to spoilage organisms).

Natural winemakers will argue that adding large doses of SO2 to wine strips it of its natural complexity and character. In fact, when you add a dose of SO2 to a light red or rosé wine, it temporarily bleaches some of the color out. As a new winemaker, I found this to be very alarming. It was even more interesting to see the color bounce back over the course of a few days. I agree, wines that are sans soufre can be more soulful and interesting. I prefer wines that are honest, real, and natural, but I also like wines that are clean and orderly. What I’ve noticed most often in the wines that I drink is that the winemakers add SO2 selectively and in low levels to keep the wine fresh and clean without tainting it with high levels of SO2. For example, a winemaker may add no SO2 at all to their wine until it’s being bottled, and then they will add a very low amount (say, 10-20ppm) to prevent oxidation and microbal growth during the transfer to bottle.

There is also controversy about allergies to SO2. There are people out there with severe allergies to this compound, usually in the form of an asthmatic reaction to high levels of SO2. In fact, when I am adding potassium metabisulfite powder to wine, getting a whiff of it feels like it sucks the air right out of my lungs. This doesn’t mean I am allergic to it, because it occurs in much lower levels in the wine than it does in the powder form. It’s just nasty, toxic stuff (the EPA has classified it as an air pollutant). The truth is, most people are NOT allergic to it, and most people who experience wine headaches are actually having a reaction to the histamines that occur naturally in red wine as a byproduct of the fermentation process, and not the SO2.

My own opinion on the topic differs, though. If I drink a wine high in SO2, I get a raging headache that just won’t quit. I usually get this from white and rosé wines, and not red wines (although red wines make me feel a little congested sometimes). I am convinced that high levels of SO2 can, in fact, cause headaches in some people. I don’t think ALL wine headaches are caused by SO2, but if you notice that commercial white wines give you a bad headache and red wines don’t, perhaps it could be the culprit…

What many people don’t know is that SO2 occurs naturally in all fermented wine, since it’s a natural byproduct of the fermentation process. The active yeasts actually create SO2 in minuscule quantities during fermentation, and any sulfur sprayed in the vineyard during the growing season can also add to the total amount of SO2 in a finished wine. That’s why most (but not all) commercial wine bears “contains sulfites” on the label. If a wine contains less than 10ppm SO2, technically they do not need to put it on the label, however most producers do – even if their wine is within the threshold – to avoid any red tape with regulatory agencies.

Wine isn’t the only food product that contain sulfites. Dried fruits, processed foods such as bread and tortillas, and many other things (mostly processed) contain sulfites to keep them fresh and palatable. In small doses, sulfites are relatively harmless (except to those with an allergy) and you’d probably never know that you were eating or drinking them. I wouldn’t worry too much about it if you aren’t experiencing any discomfort, but in general we like to avoid food products and wine with preservatives and additives. Winelandia strives to curate wines with little or no added SO2 or other chemical additives.

In conclusion, sulfur dioxide is a complicated topic prone to controversy and it’s up to the consumer to ultimately decide their point of view on the topic. This is mine, and while I’m sure not everyone will agree with me, I hope that this blog post has helped you gain a better understanding of what this chemical compound is and what it does to your wine.

A special shoutout to Chris for helping me work out some of the finer details on this topic.