(WASHINGTON POST) - The annual hop harvest is just around the corner in Washington state's Yakima Valley, the agricultural area where 75 per cent of America's hops are grown, according to the US Department of Agriculture.

And as brewers and hop brokers from across the country head to Yakima's farms to sniff just-picked whole-cone hops and taste India pale ales (IPA) created to showcase different varieties, they are also going to be talking about something that sounds far more futuristic than traditional hop farming: Cryo Hops.

Soft, juicy and aromatic IPAs remain one of the hottest segments of the craft beer world, and brewers who specialise in these beers are always on the hunt for new ways to make drinkers feel like they have stuck their faces in a pile of tropical citrus or to smooth all the bitterness out of a pale ale.

Their latest weapon is Cryo Hops LupuLN2 - pronounced "loop-you-lin" - which looks like the name of a Star Wars droid, but is actually a bright-green hop powder created by Yakima Chief-Hopunion, or YCH, a major Yakima-based hop supplier.

"Brewers were coming to us and saying, 'We're making IPAs and double IPAs, and dry-hopping and double dry-hopping, and using too many hops,'" says Mr Karl Vanevenhoven, senior vice-president of operations at YCH.

You would think that selling more hops would be good for business, but instead, YCH turned to developing a new kind of hop product. Its proprietary process dramatically lowers the temperature of hops using liquid nitrogen - LN2 in the name refers to the chemical symbol - before separating the lupulin, the substance that contains the oils and resins that provide beers with flavours and aromas, from the hops' leaves and stems.

The vegetal material, or bract, is turned into another Cryo Hops product, called Debittered Leaf.

The resulting powder is much more concentrated than whole hop cones or the standard dried, milled hop pellets - YCH recommends that brewers use half the amount of regular hops - and bursting with the zesty citrus aromas and pungent dank notes that drive New England-style-IPA fans wild, without any astringency.

"Pellets can have grassier notes," says Mr Mike McGarvey, co-founder of Washington's 3 Stars Brewing, who has brewed several beers with Cryo Hops. "Powder is all that you like about hops without the bitterness."

It does not hurt that the initial batch of Cryo Hops available to brewers included some of the most popular aroma hops on the market, such as Mosaic and Citra.

Mr J.C. Tetreault, co-founder of Boston's Trillium Brewing, remembers the first time he was exposed to lupulin powder.

He had been invited to join with five other brewers, led by Dogfish Head's Sam Calagione, to produce a collaboration beer for Sierra Nevada's 2016 Beer Camp series.

"The team got talking about what we could do that was new and innovative in the hop world," says Mr Tetreault. When some brewers began talking about Cryo Hops, "my interest was piqued".

A bag was produced.

"Every time you open a bag of hops, you take a deep breath," he says. "Every brewer takes a deep breath."

And when he inhaled the magic dust, "the aroma and everything about it had the hairs standing up on the back of my neck", he says. "Wheels started turning like crazy."

Trillium is known for IPAs and pale ales with rich citrus notes, but that effect is created by dry-hopping and double dry-hopping the beer.

This was something else entirely. Last November, Mr Tetreault got together with brewer Sean Lawson of the acclaimed Lawson's Finest Liquids to experiment with lupulin powders. The result was Pow Pow, a double IPA made with Citra, Mosaic and Simcoe Cryo Hop powders, augmented with regular Galaxy and Nelson Sauvin hops.

Ratebeer.com reviewers gave it a 99 out of 100. Beer Advocate reviewers rated it "World Class" with a 96 out of 100.

"Aroma absolutely explodes from the can," one review said.

"Expect a blast of fresh tropical and citrus fruits and beyond your daily dose of needed hops," said another.

Pow Pow was a one-off, says Mr Tetreault, and the experiments continue for Trillium. "We have to see how it plays out in use," he explains.

Beers made with lupulin powder from highly regarded brewers, such as Interboro, Other Half and Burial, have earned similar buzz.

3 Stars has used powdered hops in several releases this year, including Pounding Trees, a double IPA that was double dry-hopped with Citra and Mosaic powders; and Star Dust, a beer whose name was inspired by the use of lupulin powder.

"If you want a bitter backbone, it might not be the right (ingredient)," says Mr McGarvey.

But the audience for these IPAs, he says, is "people who are not interested in the bitterness of hops. They're interested in these fruity flavour qualities".

And while most of the beers to hit the market so far have been pale ales and IPAs, 3 Stars has begun experimenting with lupulin powder in other styles.

Flip the Script, a collaboration brewed with Aslin for the Craft Brewers Conference in April, was a dry-hopped sour made with lactobacillus bacteria.

"If you're bringing in hoppiness, you can have a problem with the lacto souring," says Mr McGarvey on the reaction between hops and the bacteria. "With powder, there is less risk. I think it will lead to more experimentation."

While this is all great news for beer lovers looking for intense hop aromas and flavours, brewers are also interested in Cryo Hops for other reasons.

When hops are added during brewing, they can leave behind organic material, which joins proteins, yeast and other by-products in a mixture called trub, which gets dumped out. However, the trub has absorbed a bit of liquid - wort or beer - and that is going right down the drain.

Using powder instead of pellets, says Mr McGarvey, "is more efficient - it could be 5 to 10 per cent more. You have that much more finished beer to sell".

Mr Tetreault points to other cost benefits: "Shipping and storage rates are halved" because of smaller amounts needed. "That's a huge benefit from an operations perspective."

YCH is expecting to produce several million kilograms of Cryo Hops this year and Mr Vanevenhoven says they have "already touched over 500 breweries and we haven't really marketed it yet".

Only one year into production, "we've already doubled the size of the (processing) facility", says Mr Vanevenhoven. "I hope that's enough."