What Ingredients Are Really in Your Glass of Wine?

At its most fundamental state, wine is comprised entirely of grapes. If you leave a vat of grapes in a container over time, the naturally occurring yeasts from the grape skins will convert the fruit’s sugary juices into alcohol. This basic premise of winemaking dates back thousands of years.

However, contemporary winemaking often involves more than just grapes. While there is a growing market for ‘natural’ wines that adhere to traditional methods, most modern producers add a variety of ingredients to enhance flavours, create specific aromas, and build texture. Let’s delve into what might be swirling in your glass – and why.

Ingredients Added to Wine

Calcium Carbonate

Examples: Cool climate wines such as Riesling or Pinot Noir from Germany or Northern France.

Calcium carbonate is used to reduce the acidity of the finished wine, particularly when grapes have yet to ripen fully due to cooler climates. By lowering the acidity, it helps in making the wine more palatable and balanced. Historically, winemakers relied on blending different batches of wine to manage acidity levels.

Flavours

Examples: Chardonnay and Cabernet Sauvignon aged in oak.

Traditionally, winemakers have relied on oak barrels to impart flavours of vanilla and subtle spices to their wine. However, since only some of the wine contacts the wood, many producers add oak chips, powders, or staves to ensure a more even distribution of these desirable flavours. This method is more cost-effective and time-efficient than ageing all wine in barrels.

Grape Juice Concentrate

Examples: Inexpensive supermarket wines, often red blends.

Grape juice concentrate can enhance the colour of red wines and add a bit of sugar to smooth out the mouthfeel. This concentrate is usually derived from Teinturier grapes, known for their deeply coloured juice. Historically, richer or late-harvest grape varieties were used to naturally enhance colour and sweetness.

Non-Vegan Material

Examples: Traditional wines such as Bordeaux and Burgundy.

Artisan winemakers who avoid adding enzymes might use non-vegan materials as fining agents and clarifiers. These can include egg whites, bentonite clay, and mammal proteins. These substances help clarify the wine and are filtered out before bottling, leaving no trace in the final product. Historically, animal-based fining agents were common due to the lack of alternative technologies.

Powdered Tannins

Examples: Red wines such as Cabernet Sauvignon or Syrah.

Tannins naturally occur in grape skins and add complexity to wine. However, the winemaking process, including crushing, maturation, and environmental factors, can affect tannin levels. To achieve balance, powdered tannins might be added early in the winemaking process. Historically, extended maceration times or the use of older, more tannic grape varieties were used to achieve the desired tannin levels.

Potassium Sorbate and Potassium Metabisulfite

Examples: Wines meant for ageing, like fine reds and whites from Bordeaux and Burgundy.

These compounds are used to guard against bacteria and spoilage. Commonly used together, they help the yeast ferment efficiently and enhance the overall flavour. Potassium sorbate prevents yeast from continuing to ferment after bottling, while potassium metabisulfite protects the wine from oxidation and spoilage. Historically, higher alcohol content and strict hygiene practices were the primary methods to preserve wine.

Sulphur Dioxide

Examples: Nearly all commercial wines, especially those intended for ageing.

One of the most common additives in wine, sulphur dioxide (often referred to as ‘sulphites’), preserves the grapes and prevents oxidation during winemaking. This additive must be declared on the wine label if it exceeds 10mg per litre, as some individuals are sensitive to sulphites. Historically, sulphur candles were burned inside barrels to disinfect them, which inadvertently introduced sulphites into the wine.

Sugar

Examples: Sparkling wines like Champagne and low-alcohol wines from cooler regions.

Contrary to popular belief, sugar is not added to sweeten wine but to boost its alcohol content through a process called ‘chaptalization.’ This practice, which assists yeast during fermentation, is particularly useful in regions where grapes may not reach optimal ripeness. Historically, grape must (freshly crushed grape juice containing skins, seeds, and stems) was used to naturally increase sugar levels.

Water

Examples: High-alcohol wines from hot climates like some Australian Shiraz or Californian Zinfandel.

Water is sometimes added at the beginning of the winemaking process to adjust high alcohol levels and balance the wine. This practice helps in creating a more consistent and palatable product. Historically, blending high-alcohol wines with those from cooler vintages was a method used to manage alcohol levels.

Yeast

Examples: Champagne, other sparkling wines, and certain aromatic whites like Riesling.

Yeast is the key ingredient in winemaking, converting sugars into alcohol. Some producers use cultured yeasts to enhance specific flavour profiles. Additionally, yeast is involved in malolactic fermentation, a secondary process where harsh malic acids are converted into softer lactic acids, improving the wine's texture and stability. Historically, wild yeasts present in the winery environment were relied upon, which could result in inconsistent fermentation and flavours.

Understanding Modern Winemaking

Modern winemaking is a delicate balance of art and science. Modern winemaking is a delicate balance of art and science. Each additive and technique has a specific role: to adjust the acidity, enhance flavour, or ensure the wine's stability and longevity. By understanding these elements, wine enthusiasts can appreciate the complexity and craftsmanship that go into every bottle.

While modern winemaking embraces these advanced practices to refine and perfect wine, there is also a growing movement towards natural winemaking. Natural wines are made with minimal intervention, relying solely on the natural yeasts present in the grapes and eschewing additives and modern technology.

Modern Winemaking vs. Natural Winemaking

Modern Winemaking Practices:

• Consistency:Advanced techniques and additives allow for a more consistent product, ensuring each bottle tastes as intended.
• Stability:Additives like sulphur dioxide and potassium sorbate prevent spoilage and oxidation, enhancing the wine's shelf life.
• Control:Winemakers can fine-tune the wine’s flavour, acidity, and body to create a balanced product that meets market demands.

Possible Downsides:

• Artificial influence:Some purists argue that additives and interventions can mask the true character of the wine and its terroir.
• Allergies and sensitivities:Additives such as sulphites can cause reactions in sensitive individuals.

Natural Winemaking Practices:

• Authenticity:Natural wines reflect the true character of the grape and terroir, offering a unique and unadulterated expression of the vineyard.
• Fewer additives:Minimal intervention means fewer chemicals and additives, which can appeal to health-conscious consumers.

Possible Downsides:

• Inconsistency:The lack of control and reliance on natural processes can lead to batch variations and potential flaws in the wine.
• Stability issues:Natural wines may have a shorter shelf life and be more susceptible to spoilage without preservatives.

Both styles of winemaking have their place and appeal. Modern winemaking provides reliability and refinement, making high-quality wine accessible to a broader audience. Natural winemaking offers a return to tradition and purity, attracting those who appreciate unique and authentic expressions of wine.

Whether you prefer the precision of modern methods or the rustic charm of natural wines, each approach offers a distinct and enjoyable experience, showcasing the diverse world of wine.