A bitter row has erupted in the normally genteel world of Scotch whisky over proposed new rules that critics say would lead to a “dumbing down” of Scotland’s most famous export.

Whisky purists claim that a new classification, due to go before Parliament this summer, could undermine Scotland’s famous single malts and lead to distillery closures and job losses.

An online petition will next month be presented to the Department for Environment, Food and Rural Affairs in an attempt to stop the introduction of a “blended malt” category to describe Scotch made of malts from different distilleries.

Titled “No! to Blended Malt Scotch Whisky”, the campaign argues that the move would cause confusion among consumers by combining the descriptions of the two main types of Scotch – blended whisky and single malt whisky. Although whisky combining different single malts has been sold for years, it has until now been covered by a variety of terms, including vatted malt or pure malt.

The new category, put forward by the Scotch Whisky Association (SWA), the trade body for the industry, was described by one independent distillery yesterday as an attempt to promote the interests of larger companies such as Diageo and Pernod Ricard at the expense of smaller firms.

Mark Reynier, the managing director of Bruichladdich distillery on the Isle of Islay, said: “The term blended malt is ambiguous. It seems like a deliberate attempt by the members of the SWA to increase the value of some of their blended whiskies.”

Jim Murray, author of Jim Murray’s Whisky Bible, said that the new category was potentially the biggest mistake in the industry for 100 years.

“It is boom time for the industry but this is totally confusing and it has to be stopped.”

The petitionhas been put forward by John Glaser, founder of the specialist Scotch whisky maker Compass Box. It says: “The main problem stems from the fact that ‘blended Scotch whisky’ (the term currently used to describe a blend of grain whisky and malt whisky) is not understood by most Scotch consumers. Further, the word ‘blend’, in relation to Scotch whisky, is associated with bad or inferior in the minds of too many people.”

The five categories being put forward in the legislation, intended to consolidate the definition of Scotch, are: single malt; single grain; blended malt; blended grain; and blended whisky (a mixture of malt and grain whiskies).

The blended malt description has been used with increasing frequency in recent years, and has seen strong sales growth.

A spokesman for the SWA said: “The proposals are aimed at trying to protect consumers and to promote to protect the interests of the industry as a whole, covering both large and small companies, and all types of Scotch whisky, whether blends or singles.”

One anonymous signatory to the petition said: “Another example of big-business chicanery imposing a development on the market that the customer doesn’t want and, in the process, eroding the hard-won reputation for uniqueness and quality of the single malt product.”

Another added: “A blend is a BLEND. A malt is a MALT.”

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