All about units
The alcohol in every alcoholic drink is the same stuff, ethanol, and works on the body in the same way. But because drinks vary in strength and in the size served, the system of "units" is used to allow an easy comparison between the amount of alcohol in a pint of lager, a glass of Chablis, or a Mint Julep.
This is worked out from the %abv (alcohol by volume) multiplied by the volume. 1 unit in the UK is equivalent to around 10ml of pure alcohol. To make this easier to apply to real drinks, approximate measures of 1 unit are based on a common size of serve at an average strength of the popular drinks categories. 1 unit is therefore defined as:
25ml of spirits at 40% abv (40% abv x 25ml = 10ml pure alcohol) 125ml glass of wine at 9% abv (9% abv x 125ml = 11.25ml pure alcohol) 1/2 pint (284ml) of ordinary strength lager, beer or cider, usually 3.5% abv (3.5% x 284ml = 9.94ml pure alcohol)
It is worth noting that most modern wines are stronger than 9%, and many people usually serve a larger measure than 125ml. (A bottle of wine is 750ml, so if you are pouring this size you would be getting 6 glasses per bottle). A large (250ml) glass of wine at 12% abv would contain 3 units.
Similarly, many modern beers are stronger than 3.5%. A 330ml bottle of 5% premium lager would contain approx 1.5 units.
Most spirits are between 37% and 43% abv, though they can range much higher than that so if you are using a new product then always check the label. Liqueurs are generally between 15% and 40%, though again it is worth checking the label to be sure.
The simple way to work out approximately how many units are in a mixed drink or cocktail is based on the number of standard 25ml measures and the strength of the ingredients. For example, a swizzle containing 1 measure of Jim Beam (40% abv) and 1 measure of BOLS (20% abv) would contain:
1 measure 40% abv = 1 unit
+ 1 measure 20% abv = half a unit
= 1.5 units
For simplicity, units are usually rounded up to the nearest half; so in the example above, a swizzle with 1 measure of Jim Beam and a measure of Sourz (15% abv) would also be counted as approximately 1.5 units.
Beyond good practice in responsible drinking, the law has serious sanctions regarding drunkenness. If you are serving in licensed premises:
• It is illegal to serve alcohol to someone who is drunk
• It is illegal to allow a customer to become intoxicated on your premises
• It is illegal to serve customers under the legal drinking age of 18.
How to recognise drunkenness
Alcohol is absorbed through the stomach and intestine, going straight into the blood stream and rapidly reaching the brain. It affects us all in different ways, but generally people tend to go through several similar stages when becoming drunk:
• Stage 1: Happy - relaxed, talkative and sociable
• Stage 2: Excited - emotional and erratic, thinking and movement affected
• Stage 3: Confused - disorientated, loud and obnoxious or out of control
• Stage 4: Lethargic - unable to talk, stand or walk
As a rule of thumb, look out for:
• drowsiness
• aggression
• carelessness with money
• altered speech patterns, slurring words, people loosing their train of thought
• clumsiness
• glassy-eyed looks or guests losing eye contact and concentration
How to deal with drunkenness
The most effective way of dealing with drunkenness is to prevent it in the first place. If a guest seems to be drinking too quickly, suggest politely he or she slows down or has a bite to eat. Here are some ideas for recognizing and dealing with drunkenness:
• keep track of how much all your guests are drinking
• engage them in conversation when serving drinks, so you can monitor their mental alertness
• try not to make judgmental statements, like "you're too drunk" or "you’ve had too much", take a calm and concerned approach and be diplomatic
• stay in control - never overreact or argue back, even if the guest becomes aggressive
• suggest calling the guest a taxi or ringing a friend
• if the guest is part of a group, enlist support from others who seem more sober