Why do white wines work with low alcohol levels while red wines don’t? A crisp, sharp Sauvignon is delicious with 8.5 % ABV while a Merlot or Syrah will feel thin, anaemic and watery. The answer is in the elements that make up the mouthful of wine.
The taste of wine is a balance between alcohol, acid, sugar, and tannin. Typically a wine maker will try to achieve the same levels of each element to create a harmonious taste. Too much astringent tannin and not enough alcohol, and the wine will be overwhelmed by bitterness. Successful lower ABV wines are the ones where these elements round out together at a lower alcohol point.
Let’s start with the tannin: this is found in the skins of purple grapes (from which red wine is made) so red wines are rich in it. It’s the mouth-puckering astringent taste that you get in a good Barolo or Montepulciano. The higher the tannin content, the more that bitter complexity needs to be balanced with high alcohol levels – which is why wines with lots of tannin, such as cabernet sauvignon, (the most grown grape variety in the world) are typically 14.5% abv or more: it’s all about the harmonics. To achieve high alcohol levels, the grapes are grown in warmer climates and left longer on the vine so more of the sugar in the grape ferments. Therefore the great Cabernet Sauvignon regions are all in hot regions (including Australia, the south of France and California). By contrast, wines with little or no tannin do not need that extra alcohol and are harvested earlier and grown in cooler countries – New Zealand, Germany, Austria and Northern France.
White wines do not, on the whole, contain tannin but are higher in acidity than reds. This gives a sharp, lively taste to the wine, that zing that we get from a good Pinot Grigio. Wines lacking in acidity are often described as flabby, soft or insipid. Acidity naturally decreases as sugar content/potential alcohol increases, so to ensure a balanced wine with good acidity, vintners grow grapes in cooler settings and pick them before the acidity drops too much while the sugar content is still lower. This is why the great wines of cooler northern France tend to be whites: Champagne, Muscadet, Pinot Gris, Sauvignon, Chenin Blanc, while those of the south tend to be red. And this is why acidic white wines balance perfectly with lower alcohol – it’s what works in nature. The great Sauvignon Blanc, that triumph of low alcohol wine production, is a perfect example with its zesty acidic gooseberry and flowering currant flavours marrying comfortably to a lower ABV.
Acidity and tannins also need balancing out with the final ingredient: sugar, traditionally supplied by the remaining sugar in the grape that has not turned to alcohol. This adds a further rounded, slippery sweetness to the wine, and offers a counterpart to the sharpness of the acidity or the astringency of the tannin, just as a good salad dressing benefits from having its lemon juice or vinegar rounded out with a little sugar. It’s not that the acidity/tannin is knocked back by sugar: it’s more that its sharpness works better with a background of sweetness behind it. Imagine the taste of lemon juice in water: it’s thin and sharp. Now imagine it with some sugar syrup added, turning it to lemonade. It may still taste sharp, but the sharpness has something to play against, and the whole taste has more depth and complexity, offering a fuller richer taste.
The final factor in good wine is body: the rounded complex mouthfeel of a good wine, that oily viscosity that gives a wine its body and heft and which can risk disappearing as the alcohol level is lowered. Low alcohol wines often replace lost alcohol with sugar to get the same rounded chewy taste – this is why slightly sweeter wines like Moscatel can be lower in alcohol and still feel as if they have body.
So, bearing all this in mind, if you’re seeking out lower alcohol wines, you will be on safer ground buying either acidic wines (like Sauvignon or Riesling) or ones with more sweetness (like Eiswein). If you’re still trying to find a good low alcohol red (hard, because see above), you should start by looking for wines made from grapes that grow best in cooler wine-growing regions (try Gamay or Pinot Noir – Beaujolais is a potential option). If you’re trying to find a good low-alcohol chardonnay, something of an absence in the low-alcohol whites, again look first at the whites from the chardonnay grape grown in a cooler region, such as Chablis.
Knowing a little about how the flavour of wine is constructed will help you avoid making optimistic but unfortunate experiments. Insisting you want a full-blown Malbec, (one of the wines highest in tannins), but with lowered alcohol will only lead to sad watery disappointment.