Maker’s Mark just got a little less stiff. The bourbon brand, known for its bottles sealed with red wax, told customers today that it’s reducing the amount of alcohol in the beverage in order to meet rising global demand.

Bourbon, which is a form of American whiskey distilled from corn and other grains, has surged in popularity over the past few years. In its largest market, the United States, bourbon now accounts for 35% of all spirit sales as more Americans have developed a taste for high-end whiskey, which is typically aged in charred white oak barrels for six years or longer. In the 1960s and 1970s, Maker’s Mark was famously sold with the slogan, “It tastes expensive…and is.”

But international growth is what’s driving demand for bourbon makers like Beam Inc., which produces Maker’s Mark as well as Jim Beam, a cheaper and more popular bourbon. Beam executives earlier this month said Australia, Germany, and Japan were strong markets. Last year, the company warned it didn’t have enough supply to keep up with bourbon demand. It also raised prices.

In an email today to loyal customers, Beam executives said the company had decided that the only way to keep up with demand was to make its bourbon less strong, stretching the current supply. ”We’ve worked carefully to reduce the alcohol by volume (ABV) by just 3%,” the email said.

I’ve reached out to Beam to clarify whether the alcohol is being reduced by 3%, as the email says, or three percentage points, which would be more dramatic. The footer of today’s email suggests it’s the latter, describing Maker’s Mark as a 42% ABV beverage, which is also known as 84 proof; it was previously distilled to 45% ABV, or 90 proof. That would be a 6.7% reduction in the amount of alcohol.

“We have both tasted it extensively, and it’s completely consistent with the taste profile our founder/dad/grandfather, Bill Samuels, Sr., created nearly 60 years ago,” two of the company’s bourbon heirs wrote in the email. “We’ve also done extensive testing with Maker’s Mark drinkers, and they couldn’t tell a difference.”

Watering down the drink is a risky move for a brand with customers as particular as Maker’s Mark’s, which explains why it reached out to its “ambassadors” to disclose the change and potentially head off a backlash. Bourbon connoisseurs often speak in reverent terms about the “taste profile” of their favorite spirits, and producers like Beam heavily market the time-honored and precise recipes that make their products superior. Adding a little water to the drink is an easy way to increase Beam’s margins and do more with less, but at what cost? Some customers, of course, prefer their whiskey over ice or with a splash of soda, but they would surely say that watering down the drink is their prerogative alone.

Here’s the email that Maker’s Mark sent today, which was passed along to me by David Weiner, editorial director at Digg: