What is it?  Can you taste it?  How much acid is in wine? Is it necessary to have acidity? These are many of the commonly asked questions about acidity in wine.  Understanding acidity helps us to identify which wines we like and to better be able to pair wines with our favourite foods.

If you taste a wine that you find to be refreshing yet slightly tart, this is the result of dominant or prevalent acidity.  When someone says a wine is crisp, bright or fresh, it means the wine has great acidity.  Although these terms are most commonly referred to when discussing white wines, some red wines can be crisp, bright and fresh as well.

The common misconception is that some wines have acidity while others don’t, but all wines have acidity. Even in a wine such as Cabernet Sauvignon, which is normally thought of as deep and mellow, acidity helps blend all the other flavours of the wine. If a wine has no acidity at all, it tastes dull and flat. It is acidity that makes the wine appeal to your taste buds and enable you to recognize all the various flavours.

Acids are one of the four fundamental traits in wine; the others are tannin, alcohol and natural sugar. Acidity gives a wine its tartness. The amount of acidity varies depending on the type of wine.  Most range from 2.5 pH to about 4.5 pH on the acidity scale.  The lower the acidity the higher the pH level.

There are several different types of acids found in wine. The most prevalent acids are tartaric acid, malic acid and citric acid.  The amount of these acids in your wine will determine how much of a puckering sensation you experience in your mouth.

In wine tasting, “acidity” refers to the fresh, tart and sour elements of the wine which are evaluated in relation to how well the acidity balances out the sweetness and bitter components such as tannins.

The natural sugar content in a wine can disguise the acidity, making the wine seem smoother with a reduced puckering sensation.  An extreme example of this would be to compare the juice of a lemon with a glass of Coca-Cola.  Both have a pH acidity level of 2.5 but the intense puckering sensation of the lemon is not felt at all when you take a sip of the cola.

Acidity acts as a buffer to preserve the wine longer so high acid wines are more likely to improve with age. The stability of high acid/low pH wines helps during aging. Conversely, high pH wines are more prone to contamination. Microbes or other unstable components can make high pH wines appear hazy.

The type of acid present in a wine can also affect our perception of sourness and the puckering sensation. During the aging process, a wine’s malic acid is often converted to lactic acid, which results in a smoother, less tart-tasting wine.

Another facet of wine that can be confusing is a wine’s total acidity. This is something that’s often noted on a wine tech sheet or in the wine maker’s notes.  Total acidity tells us the concentration of acids present in wine, whereas the pH level tells us how intense those acids taste. For example, if you have a wine with 6 grams per litre total acidity and a pH of 3.2, it will taste more acidic than a wine with 4 grams per litre total acidity with the same pH level.

A higher acid white wine will be lemonier in flavour, making your mouth water and pucker a little.  Red wines with higher acidity are more likely to be a bright ruby colour, as the lower pH gives them a red hue. Higher pH, less-acidic red wines can take on a blue or purple hue. Wines with lower acidity can also take on a brown colour because they’re more prone to oxidation. It may not be as noticeable in red wines but can be off-putting in young white wines.

Unripe grapes have high acid levels that decreases as they ripen. Grapes grown in cooler climates usually contain higher acidity because there’s less warmth and sunshine available to increase grapes’ sugar and pH levels.

When pairing wine with food it’s helpful to consider the tastes found in a dish, whether it be sweet, sour, bitter, salty, fatty, etc. With a wine having a higher level of acidity, you’ll notice that sweetness, saltiness and fat balance the sour taste of the acidity.

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