Wine has plenty of characteristics that determine its quality and its taste. Among them, wine acidity is one of the most important. And thus, wine experts pay special attention to a wine’s acid levels and have created many terms to describe it. This article will discuss why wine acidity is crucial, where it comes from, and how vintners can affect it.

What Is Acidity in Wine?

When talking about acidity in wine, we mean the level of acids in wine. Acids occur naturally in wine grapes (as well as in many other fruits and vegetables). And they are essential to prevent spoilage and also to balance a wine to make it an enjoyable beverage. Acidity gives wine sour notes and a perceivable freshness.

There is not just one acid, though. Actually, there are various types, and the following four of them are crucial:

Tartaric Acid

The most important acid in wine is tartaric acid. It’s very durable, and that’s why experts call it a fixed acid. It’s a crucial factor in stabilizing flavors and also wine color. However, not all of it is soluble. Sometimes, you might see tiny crystals in wine that look like shards of glass. These crystals, also called “wine diamonds”, are insoluble tartaric acids.

Malic Acid

The second important type of acid is malic acid. It keeps vines and grapes (and many other fruit trees and bushes) healthy, especially when they’re young. When the vines get older, their grapes typically contain less malic acid.

Malic acid is perceivable in wine. You can sense it as green fruit flavors, in particular apple or pear notes.

Sometimes, wine can contain too much malic acid. In this case, vintners let the wine undergo a process called malolactic fermentation. During this process, malic acid is transformed into lactic acid.

Lactic Acid

Lactic acid is mainly created during the fermentation process, not only in wine but also in food products like yogurt, sauerkraut, or sourdough.

Winemakers intentionally encourage the creation of lactic acid by adding special bacteria to the wine that start malolactic fermentation. The reason is that lactic acid gives the wine a buttery, creamy mouthfeel and contributes to its complexity.

Citric Acid

Wines typically have only a little bit of citric acid, and winemakers usually add it artificially after the fermentation to increase the total level of acidity. Nevertheless, it’s a relevant type of acid because it has a very aggressive taste.

Why Is Acidity Important in Wine?

Acidity is a crucial component of wine and a deciding factor for its quality. However, there is no specific level that is perfect for any type of wine. Vintners always have to balance acidity and other characteristics such as alcohol, sweetness, tannins, and aroma.

Mismatches can result in very unpleasant wines. If the acidity level is too low, the wine tastes dull, and it lacks the refreshing sensation that makes especially many white wines special. On the other hand, too much acidity makes a wine taste tart because it coats other flavors.

Besides, acidity determines a wine’s aging potential. In combination with sulfur, it protects the wine from harmful bacteria that might cause it to spoil. Without it, wine aging wouldn’t be possible.

What Determines Wine’s Acidity?

Wine’s acidity depends on multiple factors. Vintners can influence some but not all of them. These are the factors that determine acidity in wine:

  • Grape Variety: Some varietals naturally have a higher acidity level than others. By selecting the variety, vintners can predetermine how acidic the resulting wine will be.
  • Soil: The soil in which vines are planted can alter grapes’ acidity. Dense soils, for instance, can hold more water that keeps the vines’ roots cool. And this leads to higher acidity levels in the grapes.

More Details on Soil: WHAT IS TERROIR AND HOW DOES IT AFFECT WINE?

  • Climate: The same varietal has a higher level of acidity when grown in a region with rather low temperatures. That’s the case for most Old World wine countries such as France, Germany, or Italy. In warmer places in the New World, including Australia, South Africa, or California, the same varietal would have less acidity.
  • Ripening Stage: The longer grapes stay on the vines, the more sun hours they will enjoy and the riper they will be at harvesting time. And the riper they are, the less acidity they will have. So vintners can alter the grapes’ acidity by setting an earlier or later harvesting date.
  • Aging: When wine ages in oak barrels, its acidity changes. Exposure to oxygen starts a process called malolactic fermentation. During this process, the malic acid is transformed into lactic acid, which is less dominant. As a result, the overall level of acidity decreases and becomes perceivably softer.
  • Addition during Winemaking: Vintners can add acid artificially, typically after the primary fermentation. Reasons for doing this range from changing the wine’s color to altering aromas to optimizing balance.

What Is the Difference Between Acidity and Tannins in Wine?

Both tannins and acid are natural components in grapes. But they contribute very different characteristics.

Acidity is what contributes sour notes and a bit of sharpness to the wine’s flavor profile. It’s mouthwatering and refreshing and makes the wine taste bright and crisp.

Tannins are quite the opposite: They create a puckering, mouth-drying sensation that many wine lovers enjoy. Also, they add subtle bitter notes to a wine.

More Details on Tannins: WHAT ARE TANNINS AND WHAT DO THEY DO IN WINE?

Both acid and tannins are necessary for an excellent wine. They balance each other but also sweetness and alcohol to create a well-rounded drinking experience. Also, they give the wine the ability to improve when aging in oak barrels.

Does Wine Acidity Change with Age?

No, and yes. Technically, the acidity level of acidity in wine doesn’t change while it ages. So if you measure it before and after aging, the result will be more or less the same.

However, your perception when drinking the wine will most likely change. As wine ages, aggressive acidic and tannic notes soften, so it becomes a more balanced and enjoyable drinking experience.

Is There Wine Without Acidity?

No, there is always acidity in wine. As it’s a natural and necessary component for grape health and wine preservation, making zero-acidity wines is impossible.

But although all wines contain acid, you might not always sense it when drinking them. Read the following paragraphs for more information on low-acidity wines.

Wine Acidity by Varietal

As mentioned before, different grape varieties naturally have different acidity levels, even when grown under the same conditions. We’ll discuss the most and least acidic varietals and the wines made from them in the following paragraphs.

Red Wine with High Acidity

In general, even the most acidic red wines have less perceivable acidity than whites. Nevertheless, you can experience differences when comparing various reds to each other.

On the higher end of the scale are light-bodied wines such as Pinot Noir, red Burgundy, or Blaufränkisch wines. But medium- to full-bodied wines like Sangiovese, Barolo, Nebbiolo, and Tannat can be high in acidity, too.

Red Wine with Low Acidity

Red wines that are comparably low in acidity are Cabernet Sauvignon, Dolcetto, Grenache, Merlot, and Tempranillo. The same is true for off-dry red sparklers like Lambrusco and sweet dessert wines such as Ruby and Tawny Port wines or Marsala.

White Wine with High Acidity

Light- and medium-bodied white wines often are very acidic, especially when they come from an Old World wine country such as France or Germany. Among them are, for instance, Chenin Blanc, Grüner Veltliner, Sauvignon Blanc, Verdelho, and dry Rieslings. Off-dry or sweet variations such as Riesling Spätlese (English: late harvest) do not necessarily belong to this category, though.

Many dry sparkling wines, including Champagne or Prosecco, are high in acidity as well.

Cabernet Sauvignon Grapes

Cabernet Sauvignon Grapes

More Details on Champagne: THE COMPLETE GUIDE TO CHAMPAGNE SPARKLING WINES

White Wine with Low Acidity

If you are looking for a white wine with low acidity, you should focus on New World wines, especially oaked styles. For instance, Chardonnay from California or Australia tends to be relatively low in acidity. Other low-acidity whites are Gewürztraminer, Müller-Thurgau, Muscat, Semillon, or Viognier.

Most sweet whites are only slightly acidic, too. Check out late harvest wine, ice wine, or sweet sparklers such as Moscato d’Asti. Spanish Sherry and other fortified white wines usually belong to this category as well.

Be aware that even low-acidity whites usually feature more intense acidic notes than most reds.

How to Measure Wine Acidity

Acidity can be measured in two ways. One is the pH value, with pH standing for “potential of hydrogen”. The pH scale ranges from 0 to 14. Liquids with a pH value of 7 are considered neutral. Those with a lower level are “acidic,” and those with a higher level are “basic” or “alkaline”.

The easiest way to determine the pH value is a litmus test. When put into the wine, this paper stripe will change its color based on the wine’s acidity. As paper stripes aren’t the most reliable tests, winemakers tend to use other, more sophisticated methods such as digital pH meters.

Another measure is the TA value (total acidity). It quantifies the acid content in grams per liter (short: g/L) of wine or as a percentage. For instance, 7 g/L equals 0.7%. Like for pH, vintners can use simple test kits or digital devices like an acidity titrator to determine their wine’s TA-value.

How to Describe Wine Acidity

Wine lovers use a wide variety of words to describe acidic notes. Some of them have a positive connotation to express that a wine has a good, well-balanced level of acidity; others have a negative meaning and are used to describe a mismatch of the wine’s characteristics.

Positive Terms

  • Crisp: Dry wine with perceivable acidity with only mild fruit flavors.
  • Brisk: Unoaked wine with a good level of acidity.
  • Fresh: Acidic wine that often has flavors of green or citrus fruits.
  • Bright: Describes acidic wines with a watery consistency and a light color.
  • Racy: Wine with lively acidity and a relatively light body.
  • Zesty: Another term to describe light-bodied wines with a perceivable acidity level.

Negative Terms

  • Green: Used for overly acidic wines.
  • Tart: Another term to describe acidity that is too dominating.
  • Lean: For wines that have a good acidity level but lack fruity aromas.
  • Flabby: Wines that lack acidity.
  • Dull: Similar meaning as flabby.

More Terms to Describe Wine: HOW TO DESCRIBE THE TASTE OF WINE LIKE AN EXPERT

Pairing Food and Acidic Wines

Wines that are high in acidity are more food-friendly than low-acidity wines. So you have more options to create delicious matches. Of course, the best food and wine pairings also depend on other factors such as wine body, sweetness, tannins, and aromas. Nevertheless, acidity gives you a rough idea of the foods that match with it:

In general, wine should have at least an equal level of acidity as the food. Otherwise, it might taste flat and boring. Typically, a wine that’s a bit more acidic than the meal is even better. For instance, a pasta dish with tomato sauce requires an acidic wine to match the tomatoes’ acidity.

Fatty and creamy dishes call for high-acidity wines, too. The same is true for meals that contain a lot of cheese. The acid helps to cut through the savory texture and rounds out the flavors of both food and wine.

Acidy is also a good counterplayer for fried foods. Acidic sparkling wines can even stand very spicy fried dishes, for instance, from Asian cuisine.

Another great match is salty food because the wine’s acids balance the saltiness on the palate. Fish is a fantastic example: Just like you squeeze a bit of lemon juice over your dish, you can enjoy it with a glass of acidic wine. Salty cheeses also are delicious with acidic wines.

More Cheese and Wine Pairings: WINE AND CHEESE – 20 GREAT PAIRINGS FOR YOUR PARTY

Final Words

Wine acidity is a crucial characteristic. It determines the balance and thus the quality of wine, and it helps prevent it from spoiling. Without acidity, there would be no wine. So even if you dislike the sour notes it imposes on wine, you might want to toast to its presence when opening your next bottle.