VAT is governed by the EU VAT Directive with which Irish VAT law must comply. The Directive provides that all goods and services are liable to VAT at the standard rate, currently 23% in Ireland, unless there is a provision in the Directive that permits a lower rate to be applied.
While Ireland applies reduced and zero rates of VAT to a select range of goods and services under Article III of the VAT Directive, and by historical derogation, there is no means under EU VAT law to apply a lower VAT rate to the supply of non-alcoholic beer.
Any changes to VAT rates outside of what is currently permitted though the EU VAT Directive must be negotiated at EU technical working groups and ultimately agreed at ECOFIN. As with all tax files, any such changes require unanimous agreement from all Member States.