Inside a greenhouse at Colorado State University, surrounded by giant hops vines, researchers are testing a new way to help craft breweries make better beer.
Hops—the flowers that flavor beer—are most delicious when they're fresh. But when hops are harvested in late August each year, there's only a tiny window of time to use the plant before it starts to go bad. Some brewers wait for a call from a farmer and drive hours to pick up the hops; others pay to overnight them across the country. Most beer is made with dried hops, the equivalent of using dried herbs in cooking instead of herbs fresh from the garden.
The researchers are testing new methods for growing hops indoors, using LED lights to optimize growing conditions. In theory, fresh hops could be grown locally near breweries all year, with fewer resources and less impact on the environment.
"This system allows us to have five potential harvests per year, so now the brewers can make wet-hop beer more often," says Bill Bauerle, a plant physiologist and professor at Colorado State.
Philips Lighting partnered on the new research facility, which will use the company's LED lights. "When we look at the application of LED technology into production, we don't just look at it as light, we look at it holistically—what other beneficial effect are we seeing with the effect of light on irrigation practices, to nutrient management practices, to soil and substrate and nutritional content," says Ron DeKok, director of Philips' horticulture LED lighting program.
In preliminary results, the essential oils in the hops—the part that gives the flavor—seem to be much higher when they're grown in a greenhouse. The acids that give the hops bitterness may also be elevated. "It makes for a different, unique beer," says Bauerle.
The hops are grown hydroponically, a method that doesn't use soil, which concentrates flavors. It also saves water. As the researchers develop the technique, they also plan to begin recycling the water and fertilizer, dramatically reducing both, and avoiding the runoff that happens on fields.
The researchers are testing every aspect of the greenhouse—humidity, lighting, plant spacing—to learn how to help hops grow best. The light requirements are similar to tomatoes, which are often grown in greenhouses now. Because greenhouses only get natural light for a set number of hours each day, and the light isn't direct, the LED lights help make up the difference.
Though some other crops—like fast-growing, short herbs that require less light—can be grown in windowless vertical farms with no sun, it's most likely that indoor hops farms will be greenhouses with supplemental light, like the prototype at Colorado State.
It's possible to use the greenhouse to recreate the conditions in other areas, like the Yakima Valley in Washington where many hops are grown now, or, say, Czechoslovakia, where a certain popular variety of hops comes from.
The ability to grow anywhere might also help alleviate hops shortages in the future, because the hops can be grown in predictable conditions. Around 75% of tomatoes in the U.S. are now grown in greenhouses; Bauerle thinks something similar might happen for hops. The focus, at least at first, will be the "wet hop" beer market, where brewers pay more for fresh hops.
"This has the ability to provide a hop that normally just wasn't available," he says.
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