The award-winning chef has been holding talks with two Scottish microbrewers over developing the operation at the former House of Burns site, which relaunched recently after being struck by fire nearly two years ago.
The move would be in keeping with Costley & Costley's policy of making products for its venues in-house.
The company, whose nine-strong portfolio includes Lochgreen House Hotel in Troon and The Cochrane Inn, Gatehead, already has its own patisseries and bakery.
Mr Costley is also seeking tenants for two retail units next to Souter's Inn, having secured a leaseholder for a garden centre at the site. The operator, who runs family-owned Costley & Costley with wife Cath and son Andrew, said the brewery would have a ready-made customer base.
And he said the property earmarked for the operation is primed for the installation of the beer-making equipment - there are also plans to install a bottling line - and could be up and running soon.
Mr Costley said: "The property is fantastic for it. I'm looking for someone to come on site - ideally an existing brewery would transfer to there. That would be the ideal scenario for us, and I would invest in the brewery with them.
"Whoever goes in inherits big units anyway - you have got nine customers with our business anyway.
"You have got a built-in customer base, really. I want to get other attractions to take people there."
The microbrewery is not the only investment the operator is currently mulling. Mr Costley, who became a master chef at 24, is considering opening an "informal" restaurant in his native Prestwick.
He runs a bakery and coffee shop in the town, and said the public had responded well when he piloted evening meals at the cafe.
Mr Costley said: "Prestwick is quite a vibrant, evening-out town now."
The plans come as Costley & Costley anticipates a busy year this year, with 207 weddings already booked for his Brig o'Doon House Hotel in Alloway.
Mr Costley senses confidence is gradually returning to the hospitality trade after the challenges of the recession.
He said the market remains tough in Ayrshire, where he said the discount culture has made it "one of the cheapest eating out areas in Scotland". Mr Costley said the firm's next set of accounts will reveal a £2 million reduction in debt.
It reflects a move to "square off" a director's loan worth about £1m, and £500,000 paid in through the business..