The move is apparently an attempt to close the loophole which currently allows malt-based alcopops – so-called “malternatives” – to be taxed at the same rate as beer, rather than the considerably higher excise levied on alcopops.

Of course, all this assumes the soon-to-be-re-introduced bill containing the higher excise on alcopops gets passed in its current form. A similar definition of wine for taxation purposes will be included, aimed at wine-based alcopops or what the Budget papers called: “beer and wine-based products that attempt to mimic spirit based products”.

The new guidelines specify that beer must contain a minimum of four international bitterness units and no more than four per cent sugar by weight, with sugar defined as “monosaccharide or disaccharide”.

The intent is to weed out alcopops made with a token amount of hops and/or loaded up with sugary flavours to disguise the alcohol presence, but several craft brewers are concerned about their stronger beers which may exceed the unfermented sugar parameter.

“I expect they will be above the four per cent level,” Redoak Brewery’s David Hollyoak says about his Special Reserve and Baltic Porter,” and it would mean paying double the current excise.”

Hollyoak is also worried about having to foot the bill to have his beers analysed which could cost several hundred dollars a pop. “If we have to test every batch to comply that would add an extra $50-70 per keg which would take us totally out of the market.”

After being contacted by Treasury back in February, Sydney-based beer importer Franck Berges has approached the Belgian brewers’ association to see whether the range of Belgian lambic beers he brings in fall outside the proposed definition.

“All the fruit-based lambics have got a lot of sugar in them but it’s coming from the fruit rather than cane sugar,” said Berges, whose Beer Importers & Distributors has been importing international beers for more than 20 years.

Belgian lambic beers are produced by spontaneous fermentation and often infused with fruit or fruit syrups and they represent a link with one of the world’s oldest beer styles; under Mr Rudd’s regime they may be re-defined as alcopops.

“I’ve got a whole container of Belgian lambics arriving in a month and I think [Customs] will block it unless I can prove they qualify as beer,” Berges said.

While most conventional beers are well above the four international bitterness unit level, lambics are traditionally made with hops which are aged for up to three years to deliberately reduce the alpha acid or bitterness levels.

Other exotic international brews are made entirely without hops and bittered with things like pine needles and heather sprigs, while Belgian witbiers use coriander and dried orange peel. While Treasury papers indicate they are happy to accommodate an “equivalent bitterness” from such sources, it’s less clear exactly how such things will be measured.

It does seem slightly bizarre that, having failed to come up with a definition of an alcopop which can be applied to all products seen as promoting binge drinking among young people, the Federal Government has had to re-define beer for taxation purposes.