What is Acidity in wine used for?
Think of the role a squeeze of lemon plays in a gin and tonic, your fried fish, or even your homemade guacamole. That dose of acidity enhances the other flavors and creates harmony for your palate.
Without acidity , the wine would become flat and heavy, without any relief. This is what acid does so well : it balances the flavors . (see also our article on Wine Balance )
A wine is of good quality when the levels of acid, tannins , sugars and alcohol are balanced with each other. Acidity is also an essential and natural preservative.
Where does the acidity of a wine come from?
Wine contains many acids, but the two main ones found naturally in grapes are tartaric and malic acid. But what are the different factors that influence the total acidity of a wine?
- The grape variety : The grape variety will also have an impact due to its genetics. If we take the same level of maturation of a grape. Riesling or Sauvignon Blanc generates more acidity than a Viognier for example.
- Climate : Grapes grown in cooler climates generally contain higher acidity because there is less heat and sunlight available to raise sugar levels and lower the acidity of the grapes.
- Harvest date : Unripe grapes have high acid levels, but this decreases as they ripen. The winemaker has the choice of picking his grapes earlier or later during the harvest, which will have an influence on the acidity of the grapes.
- The winemaking process : A winemaker can increase acidity by adding tartaric acid to grape juice before fermentation. The process is common in warmer climates where grapes can become overripe and the acidity level too low. Winemakers can also encounter the opposite problem, in which the wine is too acidic. To overcome this, wine producers use a process called malolactic fermentation. This mechanism converts the highly acidic malic acid into the milder lactic acid.
Acidity in the mouth
Acidity is the "salivation" you feel in your mouth, on the sides of your tongue. It's what makes a wine refreshing , makes your tongue salivate and tempts you to take another sip. The easiest way to think about acidity is to think of a glass of lemonade. That salivation you feel when you drink lemonade, combined with the coolness of the lemonade, is acidity.
The words that define Acidity
When someone says a wine is lively , crisp or fresh , what they are really saying is that the wine has high acidity, just as they would say that a citrus drink tastes fresh and invigorating. If the acidity is too high, then the wine is said to be green and edgy . Conversely, if the wine lacks acidity, it is said to be flat , limp and heavy . As you can see, it is all about balance...
What is the pH of wine?
Acidity is scientifically measured on the pH scale: a lower pH indicating higher acid levels while a higher pH means lower acidity. For comparison, white vinegar has a pH of around 2.5, while milk is around 6.5. Typically, a wine's pH level will range from 3 to 4. Acidity provides some of the backbone needed for long-term aging, so wines with high acidity are more likely to improve over time than those with lower acidity.
What is Volatile Acidity?
Volatile acidity is the sum of acids present in wine that are able to "fly" or "evaporate" easily. Acetic acid is the component most often found to cause this phenomenon. It is present in all wines in moderate quantities, but when it is too high, it is considered a wine defect and gives off unpleasant aromas such as nail polish or vinegar.
Acidity and food and wine pairings
When pairing food and wine, it's helpful to first consider the flavors found in a dish (sweet, sour, bitter, salty, fatty, umami, etc.). The goal is to pair a dish with a wine that will complement or contrast with these flavors. When playing with acidity, you'll notice that sweet, salty, and fatty balance out the acidity. This is why Champagne and Brie go so well together (acidity + fat and salt). Another pairing would be to complement the dish in its flavors such as a Sauvignon Blanc and a platter of oysters, which accompanies the iodine and the acidity of the lemon juice.
