Glasgow-based St Mungo lager is set to hit the big time following a new listings deal with Waitrose and a £6.5m manufacturing investment to expand into the off-trade.

Produced by the West brewery, St Mungo (rsp: £1.69 per bottle) has been available in the on-trade since 2006 but launches into 200 Waitrose stores this week as part of a 12- month exclusivity contract.

West claims to be the only brewery in the UK to produce all of its beers to the German Purity Law of 1516, which stipulate that beer must only contain water, malt hops and yeast. The company claims St Mungo will be the only lager made to the high standards to be available in UK retail.

Waitrose expected the quality credentials of St Mungo to appeal to its shoppers.

"West is a perfect local partner for us with quality and purity at its core and a national appeal in line with our customer base," said beer buyer David Wyllyams.

"We share similar values through our desire to bring the best quality locally sourced produce to our customers and are confident we can look to roll out the supply to all of our 230 stores."

St Mungo is West's only beer currently brewed for the off-trade but it hopes to introduce its Hefeweisen, Munich Red and Dunkel lagers to retail next year following a £6.5m investment at its Glasgow plant.

As well as a fivefold increase in production capacity to 50,000 hectolitres per year, the investment will also result in the construction of a restaurant, arts space and visitors' centre in 2011.