Beermaker Craig Neuzil called Decorah Nordic Gruit "the anti-IPA."
"Everybody was making these big, juicy, India pale ales and seeing how much hop bitterness they could get into it," said Neuzil, the brewer-owner of Pivo Brewery in Calmar, Iowa.
"I said, 'Let's go the opposite way. Let's make an easy-drinking beer with zero hops and no bitterness.'"
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He landed on an ancient herbal beer style called gruit. His version is made with black walnut, bay leaf, black walnut, bog myrtle, caraway, juniper and rosemary.
Decorah Nordic Gruit has earned rave reviews, winning gold medals at the Great American Beer Festival, U.S. Open Beer Championship and World Beer Cup.
Gruit is brewed without hops, the aromatic but bitter flower commonly used in modern times to flavor beer.
"Simply stated, [gruit is] a blend of herbs that traditional brewers added to their beer in Renaissance times and before," GruitAle.com reported.
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"Herbs are essential ingredients in beer, both as preservatives and to counterbalance the otherwise cloying taste of malt."
Rock Art Brewery in Morrisville, Vermont, has brewed and served gruit for more than 20 years. The year-round accessibility of hard-to-find beer styles such as gruit is one reason the tiny Green Mountain State is revered as a giant of American beer making.
Harmony, Rock Art's signature gruit, is flavored with chamomile, elderberry, lavender and rose hip instead of hops. The same beer was known for many years as A River Runs Gruit before a recent name change.
"Some people say the combination of herbs reminds them of apple pie," Renee Nadeaux, who owns the brewery with her brewer husband Matt, told Fox News Digital.
"It also has a very tea-like quality to it."
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Herbal beers fell out of favor sometime around the 16th century, for reasons theorized among brewers and historians.
The Vikings, according to one common suggestion, fueled their maniacal battle craze by drinking gruit loaded with psychedelic herbs.
Another theory: "Some of the herbs used to make gruit had aphrodisiac qualities," said Nadeux, suggesting that the promiscuity the beer inspired ran afoul of church authorities.
Hops that replaced other herbs, however, cause a "well-documented but under-reported phenomenon known as Brewer’s Droop," noted GruitAle.com.
"In technical terms, hops are a strong anaphrodisiac for men."
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The Reinheitsgebot, the famous Bavarian beer purity law of 1516, codified the disappearance of gruit.
It dictated that beer is to be made with only water, malt and hops, an aromatic but bitter flower.
The book "Sacred and Herbal Healing Beers: The Secrets of Ancient Fermentation," by late herbalist Stephen Harrod Buhner, inspired renewed interest in gruit among American brewers and beer drinkers when it was published in 1998.
"Most beers were traditionally made with herbs that were medicinal, aphrodisiacal, highly inebriating or psychotropic," he wrote.
"These plants, and the fermentations made from them, seemed to play a crucial role in our development as a species."
Herbs in modern brewing culture are often referred to as a substitute for hops, according to GruitAle.com.
"But that’s historically inaccurate," the site states. "Hops are a gruit substitute."
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