Beer is one of the most popular beverages in the world, with nearly every country having its own local lager. In the U.S. alone, the overall beer market in 2023 totaled $116.9 billion, and breweries shipped out 192 million barrels of beer.

But the ice-cold, bubbly beverage we know today didn't always exist. So when was beer invented?

The answer traces back thousands of years. But there's still some mystery surrounding the exact origins of beer, and the beer of ancient times probably didn't taste anything like what you're used to today.

"We don't actually know exactly how [beer] was discovered," Tate Paulette, an associate professor of history at North Carolina State University, told Live Science. "Partly because of the kind of evidence we have, it's unlikely that we're going to get that kind of answer."

Because humans discovered fermentation so long ago, it's difficult to find evidence of exactly where beer-making began, Paulette explained. Much of the evidence comes from organic-residue analysis, he said.

Using this technique, archaeologists can identify the chemical signatures of grain fermentation on ancient ceramic or stone vessels. Researchers have found strong evidence of beer brewing as far back as the Neolithic period (10,000 to 4,000 years ago), when agriculture took root, in sites all around the world.