In what could be Asia’s biggest IPO this year, Suntory Holdings is planning to raise as much as ¥476 billion ($4.7 billion) by taking its food and non-alcoholic beverage unit public.

For years, Suntory has been one of Japan’s largest privately held companies. Now, like other Japanese firms helped by a strengthening yen, the Osaka-based drinks maker appears to be flexing its muscles. Suntory, Japan’s second biggest drink manufacturer and one of the world’s 20 largest by market capitalization, says proceeds from listing on the Tokyo Stock Exchange will help fund investments at home and abroad.

But why keep its liquor business, which includes the award-winning Yamazaki whisky (paywall) for which Suntory is most famous, private? Perhaps because by staying unlisted, Suntory has had the freedom to focus on the long-term, a strategy that suits alcoholic beverages. It took 46 years before Suntory made a profit from beer. Its premium whisky ages for as long as 18 years.

But it’s also a sign that all is not smooth in Japan’s alcohol industry. A shrinking as well as ageing population is drinking less beer. Last year, Japanese brewers shipped 36% less (paywall) beer than a decade earlier. Suntory’s liquor operations accounted for about 80% (paywall) of its sales for decades, but now its food and non-alcoholic beverage business accounts for over half.

And some analysts think Japan’s non-booze drinks industry doesn’t hold much promise either. “Domestic beverage demand is saturated. Whether Suntory will be attractive in the beverage industry compared with [beer makers] Asahi and Kirin will depend on its overseas strategy,” Makoto Kikuchi, chief executive of Myojo Asset Management told Reuters. “Just because the IPO is big doesn’t mean people will buy.” It may not be relaxing times ahead for Suntory.