S.77(f) of the 2003 Finance Act
[i:1qiq9hel]A relief from alcohol products tax shall be granted on any alcohol products which are shown to the satisfaction of the Commissioners in the case of wine, beer, or other fermented beverage the alcoholic content of which is entirely of fermented origin, to have been [b:1qiq9hel]produced solely by a private individual in a private premises[/b:1qiq9hel] for consumption by the producer or by the family or guests of such producer, and not to have been produced or supplied for consideration.[/i:1qiq9hel]
My interpretation of that would be that if there are commercial rates due on the premises in which it was produced then it's not a private premises. Any guarantees from the Revenue I'd make sure I had in writing.