Paul McDonald is the owner and head chef in this Michelin star restaurant in Kinsale and this is what he has to say about their breads which they offer as part of their menu.
“Our sourdoughs change often where sometimes we use Guinness instead of water sometimes a percentage of wholemeal but always 100% sourdough no commercial yeast, with our brioche and laminated rolls we use commercial yeast and with these and all our breads the are at minimum fermented for 24 hours to fully develop flavour”
Their website is here: http://www.bastionkinsale.com