When is a glass not a glass? When it's a big one, with a generous serving of a 14% abv wine in it, and you're counting units, writes Joe Breen
Did you have a glass of wine last night? How much alcohol was in it? How much did you drink? Was it a standard glass measure? And if so what is a standard glass measure? Did you read the alcohol by volume (abv) figure on the bottle? Do you think it is important? How was your head today?
If that sounds like you are locked in the vice-like grip of an opinion pollster, fear not, but those questions are pertinent, particularly as we must, for health, safety and legal reasons, ensure that we know what we are drinking and how potent it is. The strength of alcohol in wine has been steadily increasing in recent years and there is growing concern about this trend. Today it is very unusual to find a bottle of red wine at 12 per cent abv, but it is increasingly easy to find wines at 14.5 per cent abv, especially those from the new world, particularly Australia and California.
The reasons for this are many, not all of them bad. Better wine-making techniques and improved hygiene standards have allowed winemakers to keep wine "balanced" between flavour and alcohol despite the higher alcohol content typically caused by warmer growing conditions.
In his book Wine Science, Dr Jamie Goode points out that those growing grapes in a hot climate usually have to compromise on the timing of the harvest. "Pick too soon and you'll have ideal sugar levels but poor phenolic ripeness (flavour maturity). Wait for optimum phenolic ripeness and the sugar levels could be so high that the wines will be overly alcoholic. This problem is on the increase. A preference for richer, riper styles of wine may shoulder some of the blame, but so does global warming."
Marks & Spencer, a relatively big player in the wine world, has signalled that it is rethinking its position on alcohol-heavy wines. The supermarket's wine technologist, Sue Daniels, told decanter.com that "high alcohol wines have had their day. We will be trying to source more wines at 12 per cent alcohol, rather than 14 per cent, in the future." She was, however, more circumspect, when she told The Irish Times in a statement that "We are actively sourcing wines for our range at different alcohol levels from 9 per cent to 14.5 per cent in order to give customers choice. All our wines are labelled with the alcohol by volume (abv) and units of alcohol to allow the customer make an informed choice on what they drink."
Her point on labelling is important. While almost all bottles of wine sold in Ireland carry the abv rating, few translate the rating into units of alcohol. The absence of a uniform interpretation of units of alcohol throughout the EU is one of the main reasons this occurs. Perhaps it is time the EU created a standard.
The situation is further complicated by the use of different sized glasses in bars and restaurants. For instance, a 125ml glass of 12 per cent abv wine adds up to 1.5 units of alcohol. (One unit is equal to 10ml or eight grams of pure alcohol.) But a similar sized glass of 14 per cent abv wine has 1.75 units of alcohol.
However, increasingly the glasses used in restaurants and pubs are 175ml and 250ml. This translates as follows: A 175ml glass of wine at 12 per cent will contain 2.1 units, rising to 2.7 units if at 15.5 per cent. If the pour size increases to 250ml, as often offered in bars or restaurants, a 250ml glass at 15.5 per cent will contain almost four units - the maximum amount of alcohol males are advised to drink each day. In simple terms, a bottle of wine at 15.5 per cent contains 25 per cent more alcohol than a bottle containing 12 per cent.
In terms of unit intake over a week for daily drinkers, the choice of a wine at 14.5 per cent over a wine at 12.5 per cent will increase an individual's alcohol intake by 50-60g a week or five to six units. The total recommended weekly intake for men is 21 units and 14 for women. These should be spaced throughout the week. The rule with alcohol is a little every day, rather than a lot in one sitting. And those watching the scales should remember that seven calories come with each gram of alcohol.
Now how is your head? As with many good things alcohol is wonderful in moderation, and in wine it can reach its zenith. We all lose the plot at one time or another, but perhaps if we knew exactly the strength of what we were drinking it might not happen so frequently.
See http://www.aim-digest.com/gateway/ and www.drinkingandyou.com for further information