West Midlands brewer Marston’s has developed a new technology that will make real ale suitable for vegetarians for the first time.

The new ‘fast cask’ method of storing and serving cask ale will also mean cask ale can be served in places where it was previously impossible, such as trains and cruise ships.

And the Wolverhampton company will be hoping it opens up new markets for real ale.

Real ale undergoes a secondary fermentation while it is being stored in the cask, meaning that yeast is suspended in the liquid, where it turns sugar into alcohol. The brewing process uses isinglass – a substance taken from dried swimming bladders of fish – to gather up the yeast and make it sink towards the bottom of the cask.

This makes the beer unsuitable for vegetarians and vegans. It also means great care has to be taken with the transportation and storage of the casks of ale, to stop the sediment being shaken up.

But Marston’s says it has developed the idea of using ‘beads’ of yeast held within a permeable membrane to react with the beer. This means casks can be moved around more easily and stored upright, opening up new business opportunities.

Marston’s is based in Wolverhampton and runs a string of breweries such as Jennings, Banks’s and Wychwood, as well as Marston’s beer itself. It also operates a range of managed and leased pubs.

The ‘fast cask’ technology will be used first on its leading ale brands, Marston’s Pedigree and Wychwood Hobgoblin.

Marston’s is keeping details of the technology secret as it is still waiting for a patent on the invention. It is planning to officially unveil ‘fast cask’ beer during National Cask Ale Week, which starts on March 29.

Real ale has been one of the few growth markets during the recession. Supporters say this is because supermarkets – which have been taking much of the custom away from pubs by cutting prices – are unable to supply cask ale.

The Campaign for Real Ale, which has always been choosy about the methods used to produce and serve ale, has not yet decided whether the new technology is acceptable to it.