MOXEE — U.S. hop growers, the bulk operating from the Yakima Valley, are predicting they will harvest 5 percent more hops this year compared to 2014.

In spite of heat stress and water shortages that may have reduced yields, a surge in new acres driven by the expansion of the craft beer industry will push this year’s harvest to 74.5 million pounds, 3.5 million higher than last year, according to a news release from the Moxee-based Hop Growers of America.

The Yakima Valley produces more than 70 percent of the nation’s hops, used in the flavoring of beer.

The United States added 6,000 new hop acres this year, a 15 percent jump over 2014, according to the release, more than making up for reduced yields on certain varieties by 10 percent to 15 percent due to the weather this summer.

Many of those hops are still young and not producing at full volume yet, the release said, so harvest figures should continue to rise in coming years.

America’s booming craft beer industry, which favors more hops and a greater variety of them, is driving the expansion. Most growers produce on contract; some are committed to breweries up to 10 years ahead.

U.S. producers grow more than 50 varieties of hops.

European nations, the United States’ biggest competitors, also have seen high temperatures and low rainfall this year and have predicted hop harvests as much as 20 percent lower than last year, the release said. European hop growers do not irrigate.

The 2014 U.S. hop harvest was worth $272 million, according to U.S. Department of Agriculture statistics.