What Is Acidity in Wine?

Even if you find the words ‘tart’ or ‘sour’ not particularly appealing when it comes to wine, you will want your wine to have a certain degree of acidity. Without it, your wine would taste flabby, flat and dull. Think of it as a refreshing quality – the reason you want another sip. And another one. So what is acidity in wine, exactly? Let’s have a closer look.

Acidity in the Grape

What Types of Acid Occur in Wine?

Acid is one of the most important components in what makes a wine unique. A variety of different acids give the wine its balance, structure and thirst-quenching qualities. Several different acids are involved in winemaking, four of those acids are found in the grapes themselves and the other three are a result of the winemaking process. 

Acids that are naturally found in grapes:

  • Tartaric Acid
  • Malic Acid
  • Citric Acid
  • Succinic Acid

Acids that occur during fermentation:

  • Lactic Acid
  • Acetic Acid
  • Succinic Acid

What Makes Wine More or Less Acidic?

A number of factors affect the acidity in a wine. Cooler regions will produce higher acid wines, with lower alcohol and lighter body than warmer climates because the grapes struggle to ripen in cooler weather. Warmer climates sometimes produce wines without enough acidity and winemakers will need to make adjustments with a process called acidification to produce a balanced wine. 

Grapes have the highest acidity during véraison (the stage of growth just before the grapes change colour). This is why the timing of picking the grapes is so essential in winemaking. Winemakers will try to plan the best time to pick the grapes – when the fruit have achieved the optimal balance of sugar, tannin and acid. 

hand-picking white grapes

What is Malolactic Fermentation (MLF)?

There are notably a few processes where winemakers can use acid to benefit the final product. One notable process is called Malolactic fermentation or MLF where the winemaker will use a particular strain of lactic bacteria after fermentation has finished to give a buttery aroma and richness to the wine. This practice is most commonly seen in Chardonnay.

How Can You Tell if Wine is Acidic?

You notice acidity in wine by its mouthwatering effect and tingly sensation in your mouth. While a highly acidic wine can make you pucker, in a wine that is low in acidity you may find the acidity barely detectable. Evaluating acidity in a wine may be described using the following terms:

Low Acidity

These are usually warmer climate wines and can be tricky to identify due to the high alcohol content – sometimes alcohol can be mistaken for acid. Typically in these wines, the acid will be more reminiscent of Greek yogurt. Examples of low-acid wines are Gewürztraminer, Viognier, Sémillon, Tempranillo and Grenache.

Medium Acidity

Tasting a medium-acid wine is similar to taking a bite into a ripe red apple. You can taste the acid but it’s not overpowering. Examples of medium-acid wines are Pinot Gris, Pinot Grigio, Oaked Chardonnay, Extra Dry Sparkling, Gamay Noir, Cabernet Sauvignon, Merlot and Zinfandel.

High Acidity

These are wines that are lively but not quite tart, such as you might experience eating green table grapes or a Granny Smith apple – YUM! Examples of high-acid wines are Sauvignon Blanc, Chablis (unoaked Chardonnay), Dry Riesling, Torrontés, Albariño, Vinho Verde, Grüner Veltliner, Chenin Blanc, Barbera and Barolo.

oysters with white wine

Why do Acidic Wines Pair Well with Food?

Sommeliers love wines that are high in acidity because they pair so well with a variety of dishes. But why do they pair so well with so many foods? When pairing food and wine, balance is what a sommelier (or budding wine connoisseur such as yourself) is looking for. The acidity in wine balances out sweet, salty and fatty components in food. 

Acidity increases salivation, which causes a lifting effect that enhances the flavours in your favourite foods. Although it may seem counterintuitive, acidity in food decreases the perception of acidity in wine. Foods high in acid will not pair well with anything but high-acid wines, otherwise the wine will taste flat. 

Foods to Pair with Acidic Wine

Many of the most food-loving wines that sommeliers choose are high in acid. Pairings that take excellent advantage of this interaction include goat cheese with Sauvignon Blanc or Champagne with oysters, where the wine will seem softer and the fruit flavours more prominent. A tomato-based sauce served with a high-acid red wine such as Barbera would make for a rich and enjoyable pairing. In the case of very acidic foods such as shellfish and salads dressed with vinaigrette, it is best to choose a high- acid wine such as dry Riesling, Prosecco or Sauvignon Blanc. 

Getting Fresh in Cool Climates

Next time you take a sip of a fresh, crisp Sauvignon Blanc from New Zealand, you’ll be able to identify the acidity in your glass. If you want to continue learning about what makes high acidity wines – especially from cooler climate zones –so special, you’re in the right place! Read all about cool climate wines, or check out our recent interview with Calgary’s River Café wine director Bruce Soley.

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