Everything you need to know about acidity in wine
We use the word "acidity" frequently in our unique Wines With Attitude tasting notes despite the fact that consumers may be wary of the term because of the negative connotations of the word "acid". But acidity is one of the essential components of a good wine - see our previous blog on what makes a wine a good wine - though what is most important is that it should be in balance with the sweetness, alcohol and any tannins.
Hot tip: Tannins and acidity in particular can clash so avoid wines with high levels of both.
We could get scientific and talk about measuring total acidity and pH in wine but we'll keep it short and just say that wines generally have a pH between 3.3 and 3.7 which sits in between coffee with a pH of 5.0 and orange juice with a pH of 3.0.
What does acidity add to the wine?
- structure and longevity; a wine low in acidity is less likely to age well
- stability by helping to keep bacteria and microorganisms at bay
- colour; the more acid, generally the more stable, intense and more vibrant the colour
- flavours; just as lemon can lift flavours in fish, acidity makes wine refreshing or crisp and leaves you wanting more
- similarly, acidity can sharpen the aromas of a wine.
One type of acidity in wine that is not desirable is volatile acidity, essentially acetic acid or vinegar. A small amount is produced during fermentation but it increases in a wine exposed to air and in large quantities spoils the wine.
Hot Tip: If you smell vinegar or nail polish remover in a wine, send it back
Natural acidity & how it changes
Acidity is naturally present in grapes as it is in many foods and different varieties have different natural levels of acidity - Nebbiolo and Sauvignon Blanc for example are at the high end of the scale and Grenache and Viognier are at the low end.
Hot tip: White wines tend to have higher acidity than red wines
Winemakers might be tempted to adjust the acid (or the sugar - or both) and are generally permitted to do so within the boundaries of local regulations. Acidification, generally by the addition of tartaric acid, the most dominant acid in grapes, can be undertaken to increase acidity in warmer climate areas but can result in poorly made wine, especially where the adjustments are made post fermentation where the added acid has less chance to blend with the wine. A good taster can often recognise poor acidification as there is a very artificial acidic taste to the wine.
Acidity is usually naturally lowered by malo-lactic fermentation or secondary fermentation, a process often encouraged by winemakers as it softens the acidity, converting malic acid into lactic acid and carbon dioxide. Deacidification may also be permitted by adding a carbonate - and though acid levels are reduced this can leave calcium tartrate crystals in the wine. These crystals are harmless but can deter some consumers from buying or drinking a wine.
Hot tip: If presented with a dish that is more acidic than the wine, add a dash of salt to reduce the acidity of the food.
Hot tip: If you are served a creamy dish with an acidic wine such as Sauvignon Blanc, add some lemon juice or balsamic sauce to the food so that the food and wine are a better match.
Lindsay Cornelissen DipWSET, www.wineswithattitude.co.uk
© Wines With Attitude Limited
Lindsay is passionate about good quality wine and set up her online wine business, Wines With Attitude, to share that passion with other wine lovers.
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