All about alcohol in wine Alcohol is one of the components of wine, some say an essential component of wine. But with increasing concern generally about the long-term effects of alcohol on our health, should we all be considering the alcoholic strength of a wine when we decide which bottle to open? This blog looks into the alcoholic content of wine, what ABV on wine labels means in real terms and how it translates into units of alcohol. It delves into the seemingly ever-higher levels of alcohol in wines at a time when many people are seeking low or no alcohol wine. Plus an infographic with examples of high, medium and low alcohol wines. Alcohol in Wine Alcohol is a by-product of the interaction between naturally occurring sugars in grapes and naturally occurring or added yeast during fermentation. If we ignore for now fortified wines like port and sherry which have had spirit added, the level of alcohol in wine can vary from 4 or 5% up to as much as 16% (some would argue that the range should start at 0% but more about that later). What does ABV on a wine label mean? The alcoholic strength of a wine is signified by the ABV percentage that must by law be on the bottle’s label. ABV means alcohol by volume i.e. the alcohol’s percentage by volume. This means that a standard 750ml bottle of wine labelled with 14% ABV will contain 105ml (14% of the 750ml) of pure alcohol. Most of the remaining 86% is water plus some acidity, any residual sugars and the phenolic compounds which give the wine its aromas and flavours. How to calculate units of alcohol from ABV levels A survey by YouGov on behalf of Action on Smoking & Health in 2021 suggests that 75% of people in the UK want to see units of alcohol on wine and other alcoholic drinks’ labels. It would seem therefore that people are at least trying to monitor their alcoholic consumption. In the UK many drinks companies have agreed to start publishing the units of alcohol per bottle on the label though I suspect some other countries may be less willing.   The current maximum suggested levels are 14 units per week in the UK – this level has been confirmed as the maximum for both male and female consumers – sorry guys, but you can no longer say that you can drink 50% more than women. We all know how easy it can be to reach or exceed that level over a week especially in a social situation and especially given the larger wine glasses that the bars and pubs (and we ourselves at home) currently favour. But what does the ABV mean in terms of units of alcohol? To keep track of how many units you are consuming multiply your wine serving size by the ABV percentage and divide the sum by 1000 – or use the Wines With Attitude alcohol unit calculator below. For a 750ml bottle of 14% ABV wine the 105ml of pure alcohol equals 10.5 units of alcohol. One unit is therefore equal to 10 ml of pure alcohol. So with today’s large wine glass servings at 250ml, you can easily have over 3 units in just one glass of wine – that’s 4 glasses of 14% ABV wine a week to stay within the guidelines. ABV on wine labels In most countries it is a legal requirement to include the alcoholic strength on the wine’s front or back label. However it has been proven in various studies that the alcoholic strength as stated on the label is about 0.4% lower than the actual alcohol level for most Old World wines and about 0.45% for most New World wines. This falls within the EU’s tolerance level for mistakes. There is sometimes a suggestion that understating alcohol levels is done to “help” consumers avoid paying higher duty – did you know that duty on a bottle of wine at 15% ABV is currently £3.31 as opposed to £2.67 on most other wines? There are calls in some countries to make it a requirement for the alcoholic strength to be clearly stated on the front label to make people more aware. In the UK many drinks companies have agreed to start publishing the units of alcohol per bottle on the label.   What affects a wine’s alcoholic strength? Regular readers of my wine blogs will know that there are many factors which can affect the alcoholic content of wine and you can find out more in my Lowering alcohol levels in wine blogpost. These include climate, vineyard site, date of harvest, fermentation temperature, style of wine, yields, quality – and trends. ABV can range from about 5% to over 20% ABV though those at the latter end like port are fortified by adding spirit. Most still wines fall within the 11% to 15% range. Is wine stronger than it used to be? With the current and increasing trend for low or no alcohol wines, it might seem that winemakers are moving away from producing big blockbuster wines but in fact there has been a discernible trend in the not too distant past for higher alcohol in wine. One reason for the higher alcohol is global warming – hotter weather means more sugar in the ripening grapes and therefore more potential to produce higher alcohol – but there are many other contributory and more controllable factors: yeasts have been developed that can survive in higher alcohol levels therefore encouraging fermentation to last longer. Less tolerant yeast could be used instead   many winemakers took to leaving grapes on the vine for longer to encourage more complexity and texture in their wines, though both complexity and texture can be developed in lower alcohol wines with good, careful viticulture and wine-making. Something as simple as changing pruning techniques can help grapes ripen more quickly. Though it is recognised that achieving ripe grapes whilst maintaining sufficient acidity and losing