You have to pinch yourself to believe there are now some 1,400 breweries operating in Britain – the biggest number since the 1930s and 40s. Beer volumes were far greater back then but what is undeniably true today is that choice for drinkers has never been better or more diverse.

The first edition of CAMRA’s Good Beer Guide, published in 1974, listed just 40 operating brewing companies and almost without exception they produced just two types of beer – Mild and Bitter.

Today all the old beer boundaries have been swept aside as a new generation of passionate brewers offers a range that takes in Golden Ale, recreations of IPA, Porter and Stout and such innovations as beers aged in whisky casks or brewed with herbs, spices, fruit, coffee and chocolate.

In our new book Britain’s Beer Revolution, Adrian Tierney-Jones and I set out to paint a portrait of brewing in modern Britain. We could include only a small selection of breweries but we have attempted to show that beer-makers large and small are responding to genuine consumer demand for beers with taste and character.

It’s not just new-wave young brewers who are shaking up and widening beer choice. As Adrian says, “older family brewers have got their mojos back”. Robinsons of Stockport, founded in 1838 and best known for decades as purveyors of Mild and Bitter, stunned the beer world by going into partnership with heavy metal rock group Iron Maiden to produce Trooper, a modern Golden Ale.

Early in 2014, Bateman’s brewery in Wainfleet, Lincolnshire, another family brewery dating from Victorian times, rebranded their range to give the beers greater appeal to younger drinkers. They increased the strength of their dark mild to 3.6% and renamed it Black & White and then watched sales double, triple and quadruple in a few months.

Elgood’s in Wisbech in Cambridgeshire, now run by three sisters from the family, had two redundant copper “cool ships” in the brewhouse where the wort – the sugary extract created by the mashing and boiling process – used to cool prior to fermentation. The vessels had been abandoned because the wort was open to the atmosphere and could be attacked by wild yeasts.

When I suggested they should create a Belgian-style lambic beer using spontaneous fermentation the family clearly thought someone short of a few marbles had wandered into the brewery. But in 2013 Elgood’s launched a new beer, Coolship, using the copper cooling trays and I was present in February when a new batch was produced.

The boiling hot wort gushed into the trays and steam rose as it filled the trays and lapped at the rims. Head brewer Alan Pateman reminded his colleagues to leave all the brewhouse windows open when they left in the evening in order that passing wild yeasts could enter and feed on the sugars in the wort. Coolship has created great interest and is chalking up considerable sales in the United States.

Newer breweries in the past tended to be given the derogatory collective name of “minnow”. While it’s true that the owners of many micros are happy to stay small, others have grown exponentially and are now considerably bigger than many of the older family-run companies. Moorhouse’s in Burnley started in crowded, ramshackle premises where “temperance” – i.e. non-alcoholic – beer was produced. It now has large new custom-built brewery capable of producing 40,000 barrels a year.

One of the most revered new breweries, Thornbridge in Derbyshire, first brewed in potting sheds in the grounds of Thornbridge Hall. It moved to a multi-functional new brewery near Bakewell with a capacity of 20,000 barrels a year but is planning to expand to keep pace with the ravenous desire for its cask, keg and bottled products. Its Jaipur IPA is regarded as one of the finest new interpretations of the style and has won a cupboard-full of prizes.

Our area is not immune from change. McMullen is a power in the land, a family brewery from the 19th century with many pubs in Hertfordshire and an expanding estate in London. It’s been joined by several new craft breweries, including the sizeable Tring, 3 Brewers at Symonds Hyde Farm, Red Squirrel at Potten End that regularly wins prizes at St Albans Beer Festival, Buntingford near Royston that won a top award in the 2013 Champion Beer of Britain competition, and Haresfoot that has restored brewing to Berkhamstead.

May the revolution continue!