Ordnance Survey Ireland (OSI) have an online historic mapping browser that has mapping from the 1830's ("First Edition" six inch) onwards. You can access this freely from most libraries. I was involved in the building of this (the system on which it runs), but although they had digitised lots of stuff from the old maps to aid geneological research, I don't recall if they had digitised labelled buildings like breweries. I've sent a mail to my former colleagues to see if this data is available.
Another possibility is the National Inventory of Architectural Heritage[/url:3ji63vxk] from DoEHLG. This can include industrial archaeology, which [i:3ji63vxk]may[/i:3ji63vxk] also include [i:3ji63vxk]some[/i:3ji63vxk] breweries. There doesn't seem to be a search function for building use, but at least you might learn about some nice buildings in your town/townland <!-- s:) --><img src="{SMILIES_PATH}/icon_smile.gif" alt="
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<edit> I correct myself. The advanced search within the NIAH allows you to search by building use, and this includes Brewery. See this search within the Wexford Inventory[/url:3ji63vxk], or this one for Waterford[/url:3ji63vxk]for an example. There are textual descriptions of the buildings, which may or may not give background as to the brewing operations, but will certainly give details on the architectural significance of them.
I miss working in archaeology sometimes... <!-- s:) --><img src="{SMILIES_PATH}/icon_smile.gif" alt="
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