PERUWELZ, Belgium (Reuters) Full moons are often associated with tides, insanity and creatures like werewolves, but it turns out they're also good for brewing beer.
In Peruwelz, a small, sleepy town in southern Belgium, a family-owned brewery has produced its first batch of specialist beer brewed by the light of a full autumnal moon.
It isn't so much a nod to mythology as a recognition of nature's impact on the science of brewing.
"We made several tests and noticed that the fermentation was more vigorous, more active," explained Roger Caulier, the owner of Brewery Caulier, which began in the 1930s when his grandfather started selling homemade beer from a handcart.
"The end product was completely different, stronger, with a taste lasting longer in the mouth," he said.
The full moon speeds up the fermentation process, shortening it to five days from seven, which adds extra punch to the beer without making it harsh, according to connoisseurs.
The finely balanced, gold-colored beer is 10 percent alcohol by volume, extremely strong by most European or U.S. standards but not uncommon in Belgium, where traditional monk-brewed beers frequently hit 10 or 12 percent.
"It goes down very well, no problem at all," said Joseph Francois, a journalist and beer expert who has tasted the brew.
Brewery Caulier, which uses methods dating from the 1840s and is well-known for its artisanal beers, plans to produce about 12,000 bottles of its full moon beer, called Paix-Dieu (Peace-God), which go on sale on October 31.
The idea came to Caulier after he visited a friend in Alsace, a winemaking region of eastern France, who told him about how he planned his entire production schedule according to the lunar calendar.
Caulier began experimenting and eventually came up with a nine-step process that includes using two types of hops and involves a two-week secondary fermentation process inside the bottle, not unlike the technique used to produce Champagne.
"It gives the product greater fame, a bit like for great vintage wines," he said.
"It could lead to collectors checking the differences between one vintage and another because there could very well be differences between every batch."
Being from a three-generation brewing family, Caulier is fascinated by the science behind the process. But he doesn't discount the mythical aspects of full moon beer either.
"Many farmers are convinced that the moon influences the quality of some of their products," he said.
"You can feel agitated on full moons, you have births, you get many myths around the full moon and I think there is some truth behind them."
Either way, he's hoping that Paix-Dieu proves a hit and is even in talks to distribute it in the U.S. and Japan.
(Editing by Paul Casciato)