Rob Samuels, Maker’s Mark’s chief operating officer, said Sunday that it is restoring the alcohol volume of its product to its historic level of 45 percent, or 90 proof. Last week, it said it was lowering the amount to 42 percent, or 84 proof, because of a supply shortage.

“We’ve been tremendously humbled over the last week or so,” Samuels, grandson of the brand’s founder, said of customers’ reactions.

The brand known for its square bottles sealed in red wax has struggled to keep up with demand. Distribution has been squeezed, and the brand had to curtail shipments to some overseas markets.

In a tweet Sunday, the company said to its followers: “You spoke. We listened.”