Clan of the Cave Beer

Are Cave-Aged Brews Making a Comeback?

March 1, 2002 By Alan Moen

It was dusk when we reached the cave, a gaping hole in a hillside in the Basque country of northern Spain. I had hoped to visit the famous Altamira caves nearby but did not receive permission from the Spanish government in time before arriving there in summer 1993. Just by chance, I noticed another cave site on the map after visiting the ancient Basque capital of Guernica, made famous by Picasso’s powerful painting of the Fascist attack on the town in 1937.

We were running late, as usual, and when we reached the cave, the gate in front was closed. Several people lingered there. Suddenly, one of them announced that since there were enough of us now, we might as well go in. Our surprise guide opened the iron bars and led us on a fascinating journey more than 1 kilometer into the Earth, complete with a view of a few ancient paintings of prehistoric animals in one hidden recess of the cave. It was a giant step backward in time that made our entire trip worthwhile.

Caves may be in the news these days as hideouts for terrorists, but our efforts to search them out are nothing new. Caves have lured us into their depths for centuries. Natural caverns throughout the world have revealed not only the wonders of mysterious rock formations and passageways that lie beneath Earth’s surface, but also the earliest vestiges of human history. In them have been found the archeological residue of bones and skull fragments of our prehistoric ancestors, as well as the first records of human-made marks on the planet. In the caverns of Lascaux in France, Altamira in Spain, and dozens of other sites throughout the world, paintings depicting men and beasts dance across the rock surfaces of caverns that once functioned as humanity’s shelters, storehouses, and even cathedrals.

Deep in our distant past, caves provided a home for human hunter-gatherers, allowing them to escape the ravages of wet and stormy weather, as well as animal predators and other enemies. Here man made his fires, fashioned his weapons, and kept his food.

When our forebears learned to grow crops and build huts, caves still kept their useful function as ideal places in which to store food, where cool temperatures year round helped preserve it.

The Evolution of Cellaring

As human civilization evolved, caves became cellars for the keeping of beer and wine (the French word cave actually means cellar). Where natural caverns did not exist, they were dug by hand. Until the invention of artificial refrigeration in the 19th century, caves and underground cellars were the only practical way to keep beer cool in temperate climates. Many brewers hauled ice cut from rivers and lakes during the winter season into caves to keep them cooler in summer.

Tony Gomes, former brew master with the Saxer Brewing Co. in Lake Oswego, OR, recalls that during his brewing apprenticeship at the Burgerbrau Brewery in Munich, caves 15 meters underground were used for lagering their brews. “One of the guys I worked with remembered shoveling ice into them in the old days,” Gomes remembers.

Now that modern brewing techniques have largely replaced these naturally cold chambers with temperature-controlled tanks, cave aging has become an anachronism in the history of brewing, along with oak barrels and vats, wild yeast, and cask-conditioned ale.

But, fortunately for the beer lover, none of those historic means of making beer has completely disappeared, and all are currently undergoing something of a renaissance. Craft breweries and beer connoisseurs seem to be embracing these old and “inefficient” methods as a means of producing diversity and superior flavors in brewing. We may have left the cave as a dwelling place millennia ago, but some determined brewers are now going back underground in search of better beer.

Cave-Aging Today

With centuries of brewing tradition to their credit, some European breweries continue the practice of cave-aging their beers today. A case in point is Schlossbrau Stein, a brewery in Bavaria built on a cliff above the Traun River in the village of Stein. The brewery’s cellars are natural caves in the rock, where the company lagers a marzenbier for release during Oktoberfest in late September.

Kalt-Loch is another Bavarian brewery with caves, located in the Schwarzvierten or “Black Quarter” of Miltenberg, so named for the shadows that cover the area during the day. The brewery’s name means “Cold Cave” (literally, “cold hole”), since its lagering cellars are sunk into sandstone cleffs that border the Main River. Kalt-Loch’s brews are all aged in temperature-cooled tanks today. The caves are only used currently for storing filled wooden beer casks for festivals and other events.

In the Czech Republic, the birthplace of the pilsner beer style, the Klaster (Monastery) brewery has made its light and dark lagers since 1570 in natural caves where the beers are fermented in open vats and aged in wooden tanks. Yet, the beers themselves do not seem appreciably different from other Czech lagers, with clean malt flavors, ample carbonation, and a noticeable hop character, especially in the light Premium Lager version.

Grottenbier

The most recent example of cave-aged European beer is Grottenbier, a Belgian ale cellared in the limestone caves of Kanne just above Wallonia in Flanders near the Maas River and the Dutch border. Created with the blessing of Belgian beer entrepreneur Pierre Celis, this beer is kept in the caves at a constant natural temperature of about 50 degrees F. Like champagne, the beer is stored in large bottles in wooden racks and hand-turned a quarter turn each week for several months in order to evenly distribute the yeast.

A bruin, or brown, ale of 6.4 ABV, Frottenbier is a deep coppery red with an immense foamy, oatmeal-colored head. The beer has an unusual bouquet garni,  dry spicy aroma, dried fruit and caramel favors with a palate-teasing acidity, medium body, and a slightly tart, dry finish. It is a beer of considerable finesse, although how much the caves have contributed to that is somewhat questionable, since it is aged there only for three months.

The caves themselves are huge, an important tourist attraction in the region. They are also used to grow mushrooms and even to store popatoes. “You can drive a truck into them,” says Belgian importer Johnny Fincioen of Global Beer Network in Santa Barbara, CA, who led a tour to the caves in 2000. “There are two whole villages on top of the caves. But the beer is just kept in large bottles for a short time there. It seems more like a marketing thing to me.”

Ommegang

Tourism is also the major attraction of the Howe Caverns in upstate New York, where the Brewery Ommegang of Cooperstown has been aging a portion of its brews for the past two years.

According to Ommegang’s co-owner Don Feinberg, the idea for the project came from a small amount of the brewery’s bottle-conditioned Hennepin beer that was stored in a deep cellar on the grounds of the Farmer’s Museum in Cooperstown. The beer remained there from the spring of 1999 until the museum’s harvest festival in September. Feinberg and Ommegang brewer Randy Thiel were so pleased with the way the beer had aged that they began looking for a way to duplicate the experiment on a larger scale.

They found an ideal location at Howe Caverns, a group of limestone caves in nearby Schoharie County. In February 2000, 280 cases of Hennepin (the brewery’s farmhouse or saison-style beer) were lowered 40 meters (156 feet) into the caves. The beer was released as the brewery’s Christmas beer nine months later.

Feinberg believes that the cave atmosphere, similar to the caves of Champagne in France, is ideal for aging bottle-conditioned beers. “There’s a noticeable difference to the Cave Hennepin compared to the same bottled beer stored at 65 or 70 degrees,” he claims. “It’s less orangey-fruity and much drier.”

Feinberg thinks that the beer normally goes through three stages of development in the bottle: a very fruity phase for the first six months, a “dormant” phase from six to 12 months, and a mature flavor stage from about 18 months onward. He believes that cave-aging Hennepin extends this process and the life of the beer.

It should be mentioned that Feinberg and his wife, Wendy Littlefield, who have had a long career as Belgian beer importers Vanberg & DeWulf, are well aware of the marketing potential of their cave-aging experiments. Howe Caverns, with some 13 million visitors annually, is the second most visited natural attraction in New York state after Niagara Falls.

According to Feinberg, the original batch of Cave Hennepin was placed in a highly visible location “right off the elevator” at the entrance to the caves. The second “vintage” of cave beer―300 cases of Hennepin and 180 of Ommegang (their eponymous abbey-style ale)―has been moved to another spot in what Feinberg describes as a “cul de sac.” While the Hennepin was again released for Christmas in 2001, the Ommegang will be kept an additional year in the caves.

Howe Caverns have been something of a gold mine for the brewery. Cave Hennepin emerged in 2000 to rave reviews. The beer earned a Platinum Medal and a score of 96 points from the Beverage Testing Institute in Chicago.

Ommegang brewer Randy Thiel thinks the cave is a definite improvement on cold room cellaring for the beer. “The cave is a more stable environment, with little or no fluctuation in temperature, light and humidity,” he says. Since Ommegang’s brews are all corked in the Belgian tradition, the humid atmosphere of the caves also keeps the corks from drying out and letting too much air into the bottles.

There are drawbacks, however. As in any corked beer, some TCA or “corked” flavor may be transferred to the beer over time, but Thiel doesn’t see that as a flavor defect in the style of beers that Brewery Ommegang makes. “I consider myself a brewing scientist,” he says, “but it does matter that the beer is treated in a more gentle manner this way. Beer has to be in a happy place.”

Alaskan Brewing

Someone’s cave may be another’s mineshaft. In Juneau, the Alaskan Brewery decided to condition a barley wine it made in the spring of 2000 in the AJ (Alaskan Juneau) Mine, a historic gold mine in the area that is now more frequented by tourists than miners. A part of the brewery’s R&D (“Rough Draft”) program, the project was carried out by brewer Jim Laurent. The beer was brewed with pale and Carastan malts, along with a touch of peat-smoked malt, and hopped with Chinook and Goldings hops (OG 1091, 46 IBU, 9 percent ABV).

In spring 2001, Laurent moved a 14-barrel batch (28 kegs) of the beer about 100 yards into the mine, located on Mount Roberts. The beer was later placed in a specially built room about 300 yards deep, with windows so that the kegs were visible for visitors.

Laurent dry-hopped the brew and filtered it before kegging. “I worried about the hop flavor surviving so well in that cold temperature, but it came off pretty clean,” he says. “I had my doubts, but I think it’s a pretty good beer.”

Unfortunately, none of the beer was kept at the brewery for a flavor comparison. When tasted in December 2001, prior to its release for the Great Alaskan Beer & Barleywine Festival in Anchorage in January, the beer was Seville orange in color with a sweet malt nose and whisky-like smokiness; a soft, medium-full body; and a moderate hoppy finish. It seemed quite drinkable for such a young barley wine. Could this have been due to the cave aging?

Marketing Ploy or Legitimate Technique?

The question remains whether the atmosphere of a cave cannot be effectively duplicated in the brewery in temperature-controlled tanks―or in the case of bottles, room storage. Lynn Kruger, director of the Siebel Institute of Brewing, believes that tanks work as well or better. “There is no real difference between cold storage and cave storage as far as the beer is concerned,” she says. “It really depends on the type of vessel, the temperature, and the length of time. But cave aging is more romantic, and might be more practical for some breweries, because it is cheaper.”

Steve Parkes, head of the American Brewers Guild at the University of California at Davis, agrees. “Personally, I wouldn’t think that it would make a difference,” he says. “The nature of the atmosphere in the storage room, cave, or whatever is important in aging Scotch whisky, but not beer. If the tanks or barrels were made of wood, then it could be a factor.”

Parkes recalls one of the “urban beer legends” he knows related to caves. “There’s a story of a guy drilling a well somewhere in Germany and striking beer instead of water,” he laughs. “Since virtually all beer was cellared underground it the past, it could have happened.”

Even though the Katl-Loch Brauerei has caves, former brewmaster Peter Kehl thinks temperature-controlled tank storage is better for the brewery’s lagers. “You can reach a lower temperature than in the caves Low temperatures are the most effective prevention against the rise of bacteria in the beer,” he believes.

The Future of Cave Beer

While there seems to be some evidence that cave aging can create more flavor complexity in some beers, the process may be more trouble than it’s worth for most craft brewers. Suitable caves are not common to most brewing regions, and, until recently, none in North America were still used for aging beer. Underground cellars do exist in older breweries like Miller Brewing in Milwaukee.

Ironically, what was a once a simple and cheap means of storing and conditioning beer in the Old World might be more difficult and expensive to replicate here, if caves have to be dug in areas with strict land-use laws. Still, breweries located near natural caverns might wish to experiment with specialty beers like strong ales or barley wines that are meant to be laid down.

In Plato’s Parable of the Cave, mankind is seen as cut off from true knowledge, huddled in his grotto, and experiencing enlightenment only when he emerges from the cavern. When it comes to beer, that process might well be reversed―we could learn more by going back inside.