1991 UK and Ireland advert for Kaliber non alcoholic lager.

Kaliber, a brand of non-alcoholic pale lager which is sold in the United Kingdom, was launched in 1983.

It is made from hops, malted barley, sucrose and yeast along with stabilisers and CO2. The alcohol is removed by vacuum evaporation at the end of the brewing process to make it a fuller tasting beer according to the brewer.

Even though it is classed as an alcohol free beverage it still contains trace amount of alcohol, around 0.05% to be exact. This amount of alcohol is naturally occurring and cannot be removed, and this same amount is also found in fruit juices.

Info gleaned from Wikipedia