Maker's Mark is owned by spirits company Beam Inc., based in Deerfield, Ill. Its other brands include Jim Beam bourbon.
The supply shortage at Maker's Mark comes amid an ongoing expansion of its operations that has cost tens of millions of dollars.
A distillery expansion completed last year boosted production capacity by 45 percent, Rob Samuels said. Maker's last year added warehouse space for 100,000 more barrels of aging bourbon, and it expects that expansion pace to continue for at least another five years.
Maker's bourbon ages in barrels for at least six summers and no longer than seven years before bottling.
One shortcut the bourbon maker refuses to accept, Rob Samuels said, is trimming the aging process, which would increase market supplies. It also won't buy surplus whiskey from other distilleries, he said.
The supply shortage at Maker's comes amid growing demand for Kentucky bourbons in general.
Combined Kentucky bourbon and Tennessee whiskey sales from producers or suppliers to wholesalers rose 5.2 percent to 16.9 million cases last year, according to the Distilled Spirits Council, a national trade association that released figures last week. Revenue shot up 7.3 percent to $2.2 billion, it said. Premium brands, generally made in smaller batches with heftier prices, led sales and revenue gains.
Kentucky produces 95 percent of the world's bourbon supply, according to the Kentucky Distillers' Association. There are 4.9 million bourbon barrels aging in Kentucky, which outnumbers the state's population.
In the last year, Kentucky distilleries invested nearly $230 million in new and expanded production facilities, warehouses, visitor's centers, bottling lines and more, according to Eric Gregory, president of the Kentucky distillers' group. It's the largest expansion since Prohibition, he said.