SAN FRANCISCO — It was not too long ago that Owen Westman's customers at Rickhouse Bar did not even know there were Japanese whiskeys available, let alone ask for them by name.

"They certainly do now," Westman says.

Although best known for sake, Japan has a whiskey tradition stretching back more than a century. It is not widely available in the United States, but that is changing as companies like major producer Suntory work to boost overseas sales.