MISSOULA - The new canner at Big Sky Brewing Co. is the only one of its kind in the world, a revolution in the craft brewing industry.

The major lifegiving force for humans - oxygen - happens to be death to craft beer, which is generally unpasteurized and still alive when it reaches the consumer.

Craft brewers have battled against oxygen and its beer-killing ways for many years by bottling, which uses less oxygen, and leaving the canning up to the big domestics. Those firms pasteurize their beer, effectively rendering it unaffected by oxygen but also killing some of the flavor.

In the past, larger craft breweries like Big Sky Brewing Co. couldn't make use of existing canning technology because the amount of beer they produced required more speed than small, often hands-on canners could handle.

Bottled beer was the only option, because large canning machines, at around $6 million, were out of reach for all but the largest breweries.

A technology bubble burst when demand for beer in eco-friendly aluminum cans started to spike, making canning line manufacturers look beyond slower, hands-on canning lines used by smaller breweries such as Missoula's Kettlehouse Brewing Co. to the needs of larger craft brewers such as Big Sky.

Bjorn Nabozney, Big Sky co-owner and executive vice president, credited people like Tim O'Leary at Kettlehouse, who helped spur improvements to much smaller machines. "They really paved the road to make it possible for companies like us to step in and do it at speeds that are more appropriate for us."

SBC Bottling &Canning of Parma, Italy, built the can filler and seamer that Big Sky bought. The machine was developed in response to questions from other breweries about lowering the air uptake, or how much oxygen stays in the can when it's filled with beer and sealed.

New Belgium Brewing Co. of Fort Collins, Colo., bought the first-generation version of the same canner from SBC Bottling & Canning, but the second-generation machine, purchased by Big Sky, is a whole new animal. It's so advanced that the company's technicians can run it remotely from laptops on another continent.

"It's the only fully electronic can filler on the planet right now," Nabozney said. "What makes that special compared to other can lines is that we have no mechanical knocks to tell it when to purge CO2 or when to fill the can with beer. It's all done via sensors."

Because cans have seams and filling them requires exposure to the air, the slower, more manual canning machines of yesterday made it difficult for breweries to get any sort of shelf life out of a canned beer, which limited the brewery to local sales only.

At 60 cans a minute, the new filler at Big Sky isn't lightning fast, but it's airtight almost to a fault.

Sensors guide the filling process by purging the cans with carbon dioxide or C02. A small stream of water shoots to the bottom of the can, pushing air-containing foam to the top, which is scraped off before the beer in the can is blanketed with CO2 and the can is sealed.

As cans of Big Sky's Trout Slayer, a light wheat beer, were filled, sealed, packaged and shipped off recently, assistant brewer Tim Chisman checked for any oxygen, which he measures in parts per billion.

"We're usually around 20 parts per billion," Chisman said as he read the numbers off a sensor that measures dissolved oxygen. "I don't know for sure, but they (SBC Bottling & Canning) told me that Anheuser-Busch's cans run about 200 to 250 parts per billion."

In fact, the amount of craft-beer-killing dissolved oxygen in Big Sky's canned beers is lower than the company that built the machine ever expected.