Ever heard a wine expert talk about the acidity in a wine? Acidity is present in all wines. If you can remember back to your school chemistry classes, you might have a memory (distant or otherwise!) of the concept of pH, a scale used to indicate how acidic or alkaline a solution is. Water has a pH of 7; anything below that is acidic and anything above that is alkaline. Since wine typically falls between 3 and 4, it’s always acidic. So how do we detect acidity in wine, why is it important and why do wines have different levels of it? The way you detect acidity in wine is through your saliva; in short, it makes your mouth water. The higher the acidity in a wine, the more you’ll salivate when it’s in your mouth and after you swallow it. In fact, wine buyers who are tasked with tasting up to a hundred wines a day (yes, that’s been my job too; isn’t it terrible?) will use a rather undignified method of gauging the acidity of a wine – they’ll hold their mouth open over the spittoon after spitting the wine out to see how much and how quickly they salivate (!) If you can’t quite bring yourself to try this slightly weird trick at home, you can try a modified version of it – after you’ve swallowed your wine, open your mouth slightly and feel how much you’re salivating. With wines high in acidity you’ll also notice that whilst the wine is in your mouth it creates a sharp, tingling sensation on the sides of your tongue. Some clues as to the acidity level of a given wine can come from the language used to describe it: with a wine high in acidity you’ll tend to see words like ‘crisp’, ‘refreshing’, ‘mouth-watering’, ‘zesty’, ‘vibrant’ or ‘juicy’. Those lower in acidity will be described more frequently as ‘smooth’, ‘creamy’, ‘rich’ or ‘full-bodied’.
Why does acidity matter in wine? A few reasons. First, it acts as a preservative and keeps wine fresh over time. Secondly, it’s an important component of what we refer to as the ‘balance’ of a wine (more on that in a future missive) and can make the difference between a wine that feels refreshing and one that feels cloying. Finally, acidity makes wine a superb partner for food, because it cleanses the palate after each mouthful, particularly with fatty or oily foods. Try this out with some cheese; first, eat two bites of cheese in a row, noticing how the second one tastes, then enjoy a big mouthful of wine (swirl it properly around your mouth before you swallow it) and eat another bite of cheese. You’ll notice that the final bite tastes better than the one in the middle and just as good as the first. Not all wines have the same acidity levels, and the simple reasons for that can be found in two of my introductory videos, Wine = Geography and Wine = Grape Variety. Sign up here if you haven’t already. Wines from climates far from the equator will be higher in acidity, and wines made from certain grape varieties will also be higher in acidity. For example, wines from the Sauvignon Blanc grape are invariably described as ‘crisp’, ‘mouth-watering’ and ‘refreshing’. I hope this has been helpful. Having this background on acidity in wine will be very helpful to you, since it will enable you to understand more why you enjoy the styles you do, and seek them out to enjoy again in the future.