It’s good news for our beleaguered pubs that they will be able to stay open until one in the morning on 8 May as the country celebrates VE Day – the 80th anniversary of the end of World War Two in Europe.

As we raise a glass to mark the day, it is fascinating to look back and see what both pubs and beer were like at the time.

Today pubs are awash with many styles of beer, from golden lager to black stout, with IPA, pale ale, wheat beer and golden ale in between. In 1945 it was a different picture: two types of beer dominated pubs, and they reflected the sharp social divisions of the time.

Mild ale was drunk by working-class customers while the middle class consumed more expensive bitter. And never the twain should meet. Pubs were divided into public bars for the workers and saloon or lounge bars for the more affluent.

Mild was far and away the major beer of the day at a time when the working class made up the biggest sector of society. Britain was still an industrial society and there were many thirsty throats to refresh when people laboured for long hours in factories, mines and fields.

The brewing records at Harvey’s 19th-century brewery in Lewes, East Sussex, show that in the year in question, 1945, 75 per cent of production was its Dark Mild. In 1955, when Harvey’s launched Best Bitter, mild still accounted for 74 per cent of production. Today, Best Bitter is the standout beer at 84 per cent of annual output, with Mild down to just 8 per cent.

On my local patch, McMullen of Hertford still makes its delectable AK Original Mild, named Champion Beer of Hertfordshire at last year’s St Albans Beer and Cider Festival. Banks’s in Wolverhampton was a major mild producer, but that will be knocked on the head when the mad axe men at Carlsberg shutter the brewery.

Fortunately Bathams, also in the Black Country, continues to brew a superb Mild Ale, as does the major Manchester family brewer Joseph Holt.

Timothy Taylor's, renowned for its Landlord pale ale, brews two versions of the style, Dark Mild and Golden Best, the latter showing that not all milds are dark.

Proof that mild ale was not always low in strength comes from the Beacon Hotel in Sedgley, also in the Black Country. Its in-house brewery uses a 1920s recipe for its Sarah Hughes Dark Ruby Mild that clocks in at 6 per cent ABV. It has a wonderfully complex aroma and palate of blackcurrant fruit and spicy Fuggles hops.

There are many myths around mild ale. It’s said to be weaker than pale ale and bitter but historically that’s not the case, as Sarah Hughes’ beer indicates. The style dates from the 18th century and was dubbed mild as it was served young and fresh in pubs, unlike the staples of the time, porter and stout, which were aged in wood for several months.

As a result of ageing, porter and stout had a sharp and even lactic character while mild was smooth and slightly sweet.

Its mildness was enhanced by having fewer hops than the pale ales and bitters that emerged in the 19th century. Bitter was so called because it was heavily hopped and was bitter and aromatic on the palate.

As a result of restrictions on the strength of beer in World War One, mild did become lower in strength and it never recovered. For example, Harvey’s Dark Mild is just 3 per cent while its Sussex Best Bitter is 4 per cent. McMullen’s AK Mild is 3.7 per cent while the brewery’s Country Bitter is 4.3 per cent.

The beer consumed in vast quantities on VE Day was probably not of the highest quality as a result of war-time restrictions. The government had been anxious to ensure sufficient bread was available for the population and as a result, breweries were forced to cut back on the barley they used for malting. Brewers made up for this loss by adding flaked maize, flaked oats and even potato starch to their brews.

Brewers were instructed to cut back on hops as the government wanted to use land to grow fruit and vegetables to keep the people healthy and happy. Hop rates were cut by 20 per cent with the result, no doubt, that bitter was considerably less bitter.

Beer was also expensive due to a series of hefty increases in excise duty during the war. By 1945, a pint of mild was twice the price it had been in 1939 while its strength had been reduced by around 6 per cent alcohol.

The public and saloon divide in pubs was strictly imposed. The Lamb in Lambs Conduit Street in London’s Bloomsbury is a fine example of a two-bar hostelry. It even has snob screens, revolving glass screens on top of the partition between the two rooms.

In Victorian times, the screens could be revolved so that the hoi polloi in the public bar couldn’t peer into the saloon. This stopped them seeing their “betters” who might not only be their employers but were also drinking with – shock, horror – ladies who were not their wives.

Further examples of pubs with snob screens include the Prince Alfred in London’s Maida Vale, Bartons Arms in Aston, Birmingham, Posada, Wolverhampton and John Leslie in Edinburgh.

You can make your contribution to ending class divisions on VE Day by ordering a pint of mixed – half of mild and half of bitter.

As the celebration falls in May, it happily coincides with CAMRA’s annual Mild Month promotion. So, hurry to a pub and enjoy a glass of history.