Sniffing Out Wine Faults: A Guide to Better Bottles

Maryland’s wine scene is growing in size, sophistication, and statewide pride. With over 100 wineries across its 10 wine trails and several acclaimed AVAs (American Viticultural Areas), Maryland wine lovers are enjoying a more diverse and locally rooted selection of wines than ever before. However, even the best bottles—local or imported—are not immune to wine faults. Whether you’re sipping an award-winning Chambourcin from the Piedmont Plateau or a crisp Vidal Blanc from the Eastern Shore, understanding common wine flaws will sharpen your palate and appreciation for quality craftsmanship. Let’s explore seven of the most common wine faults, how to detect them, and what they mean—especially in the context of Maryland’s climate and winemaking practices.

1. Oxidation – When Wine Loses Its Spark

How to tell: The wine appears dull, with colors shifting toward brownish hues (especially in whites), and aromas resembling bruised apples, caramel, or vinegar.

What it is: Oxygen is wine’s slow assassin. A little is necessary during production, but too much exposure causes deterioration. Maryland white wines, which are often unoaked and fresh in style, are particularly vulnerable due to their lower tannin levels (tannins act as a natural preservative).

Can I fix it? Unfortunately, no. But you can prevent oxidation at home by sealing opened bottles with vacuum tools or inert gas spray. Local winemakers are increasingly investing in better closures and bottling practices to reduce this risk.

2. Cork Taint – The Infamous “Wet Dog” Smell (TCA)

How to tell: A musty odor like moldy basement, soggy newspaper, or wet dog. The fruit aromas are muted or absent.

What it is: Caused by a chemical compound called TCA (2,4,6-Trichloroanisole), this flaw usually comes from natural corks that have been tainted during manufacturing. While some Maryland wineries use real cork, many are turning to screwcaps and synthetic options to avoid this issue.

Can I fix it? No, though there’s an old myth about Saran Wrap absorbing TCA—it no longer works due to changes in the product’s materials. Just return the bottle.

3. Sulfur Compounds – The Rotten Egg Trap

How to tell: Rotten egg, burnt rubber, or skunky smells, particularly noticeable after decanting.

What it is: Sulfur is a vital winemaking tool used to preserve freshness and prevent spoilage. However, excess sulfur or fermentation issues can lead to foul-smelling byproducts like mercaptans or hydrogen sulfide.

Can I fix it? Yes, to a point. Decanting often helps these compounds "blow off." Maryland winemakers, especially those practicing low-intervention methods, carefully manage sulfur levels to balance protection with purity.

4. Secondary Fermentation – Surprise Bubbles

How to tell: Unwanted fizz in still wine, along with yeasty or sour aromas.

What it is: If a wine contains residual sugar and isn’t fully stabilized, it can start fermenting again in the bottle. This is more likely in low-sulfite, unfiltered wines—something you may encounter in Maryland’s natural wine circles.

Can I fix it? No, but aggressive shaking (with a towel over the top) can force the bubbles out. Better yet, buy from local producers with strong quality control.

5. Heat Damage – The Cooked Wine Curse

How to tell: Jammy, overly sweet smells with notes of stewed fruit, nuts, or burnt sugar. The cork may also be partially pushed out.

What it is: Heat exposure—common in poorly stored bottles—"cooks" wine and speeds up oxidation. Maryland wines often ship regionally and are less likely to experience cross-country heat stress, but it’s still crucial to store them around 55°F in a stable environment.

Can I fix it? No. Once wine is cooked, it’s permanently altered. Avoid storing wine in garages, sunny counters, or hot cars—especially during humid Maryland summers.

6. Lightstrike – UV Damage to Delicate Whites

How to tell: Smells like wet wool, wet cardboard, or boiled cabbage—most common in pale wines like Pinot Grigio or Sauvignon Blanc.

What it is: UV rays cause chemical reactions in wine that degrade aroma compounds. Many Maryland white wines are bottled in clear or light-green glass, making them more susceptible unless kept out of direct sunlight.

Can I fix it? No. Store bottles away from windows and bright light to preserve their delicate aromatics.

7. Microbial and Bacterial Taints – When Wine Gets Funky

How to tell: Animal or farmyard smells (often described as “mousy” or “gerbil cage”), hay, or metallic tang. Often found in natural or minimally processed wines.

What it is: During fermentation, wild yeasts and bacteria may go rogue if not kept in check. Some Maryland winemakers, especially smaller artisanal operations, embrace a natural approach. While these techniques can add character, they also increase the risk of microbial flaws.

Can I fix it? No. Once a wine is dominated by bad microbes, it’s irreversible.

Bonus: Not All “Flaws” Are Truly Faults

Volatile Acidity (VA): Smells of vinegar or nail polish remover can be part of a winemaker’s stylistic choice—especially in small batches of Maryland red blends made from highly ripened fruit.

Tartrate Crystals: Harmless "wine diamonds" found at the bottom of bottles, especially those stored cold. A common occurrence in Maryland white wines not cold-stabilized before bottling.

Herbal or “Green” Aromas: Grassy or vegetal notes in wines like Maryland-grown Cabernet Franc or Sauvignon Blanc are normal and varietally correct, not faults.

Brettanomyces (Brett): A wild yeast that adds barnyard or leathery notes. While it’s considered a flaw in delicate wines, some Maryland reds like Syrah or Petite Verdot might show subtle Brett and still be enjoyable.

Conclusion: Taste Smarter, Drink Local

Understanding wine faults gives you a new appreciation for winemaking skill—and a sharper nose. For Maryland wine drinkers, it’s a valuable tool in supporting local wineries that are striving for excellence amid a challenging and diverse climate. Next time you visit a Maryland vineyard—from Boordy Vineyards in Baltimore County to Crow Vineyards on the Eastern Shore—you’ll be ready to swirl, sniff, and sip with confidence. Cheers to better bottles and better knowledge!