YAMIKA — You can tell it’s fall when the smell of hops permeates parts of the Yakima Valley.
Even in downtown Yakima, blocks away from the hop warehouses near Fruit Row, that distinctive aroma fills the air.
But as fresh hops are baled and warehoused, a potential danger also rises: fires.
A recent fire near Zillah served as a reminder of how hops, which provide beer with bitterness and aroma, can catch fire if not carefully monitored.
In 2006, a fire destroyed 4 percent of the U.S. hop harvest, causing some concern among brewers.
Hops are one of Yakima County’s major cash crops. The valley’s hop yards produced the majority of the nation’s hops and are a significant percentage of the global hop supply.
While hops were first grown in Washington in Puyallup, the west-side industry was doomed by the hop louse.
But hop production flourished on the “dry side” of the state, where the more arid, sunnier climate proved more conducive to the plant. Yakima County’s hop industry went into overdrive thanks to Alexander Graham Bell — yes, that Alexander Graham Bell — and his father-in-law establishing a Moxee company to start farming in the East Valley area.
While Bell and Gardiner Green Hubbard’s farmers experimented with several crops, hops turned out to be the most productive, and eventually Moxee became the “Hop Capital of the World.” The descendants of some of the French-Canadian farmers they recruited are still in the industry today.
In the fall, the hop bines are cut down, the cones harvested and dried in kilns before being bundled or, in an innovation developed by master brewer Bert Grant, pelletized to provide better control over flavor and aroma in beers.
The hops have to be dried enough to preserve them, but not so much that they lose their flavor.
And that’s where the problems can arise.
Moisture starts problem
If there’s too much moisture, acids in the tightly packed hop bales can trigger a thermal reaction that generates heat. In turn, that can ignite the hops and the baling material encasing them, which can then spread to the other hop bales.
As a result, there have been several serious warehouse fires.
In 2019, spontaneous combustion gutted a warehouse owned by the John I. Haas company.
A year later, two hop fires destroyed warehouses owned by Haas and Hollingbery and Son, causing a total of $7 million in damages and the loss of millions of pounds of hops.
In 2006, a warehouse leased by S.S. Steiner Inc. caught fire, destroying 2 million pounds of hops — about 4 percent of the nation’s hop harvest that year.
“This will affect the U.S. market particularly because in some of the varieties, there was a feeling we were already a little short (that) year,” Ann George, the administrator of the Washington Hop Commission, said in a 2006 interview.
The fires were all attributed to spontaneous combustion.
In December 2017, a bag containing more than a half-ton of hop pellets ignited at a Haas warehouse, causing $20,000 damage, with sprinklers in the building catching fire in the early stages.
And in October, a warehouse in Zillah was heavily damaged when hops in a cold-storage room caught fire.
Along with sprinklers to contain a fire, companies use other methods to monitor hop bales for the first signs of spontaneous combustion, including having a worker scan bales with a thermal-imaging camera to look for hot spots.
