Normally, a brewery adding cans to its packaging mix wouldn't be a big deal. But when Double Mountain Brewery, Hood river, Ore., announced it was adding aluminum cans, it was a big deal.

That's because founder Matt Swihart had opened the brewery with the intent to create an enviornmentally responsible businesss, he thought packaging his beer in refillable glass bottles was more responsible than using single-use bottles or cans.

He was right about the single-use bottles, but wrong about the cans. So it's good to see Swihart now, for the first time, offering his product in aluminum cans and not just reusable bottles.

In the real world, aluminum cans are actually more sustainable than refillable glass bottles. Here's why:

• Aluminum cans or bottles can be recycled indefinitely. While new aluminum cans have high energy consumption, once the can enters the recycling stream that is reduced dramatically, making aluminum the most sustainable package.
• Glass can be sustainable, but only if it is truly reused and recycled. But its weight and energy use make it worse than aluminum in many lifecycle studies, according to Earth.org, which cites a University of Southampton study that finds while plastic bottles generally cause more environmental impact at the end of their life cycle, glass bottles have a more damaging overall effect, largely because they are heavier and require more energy for their production.
• Using a life-cycle analysis, reusable glass requires 2-6 uses to outperform single-use plastic bottles; reusable plastic or aluminum , 10-30 uses; and stainless steel, 30-90 uses.
• A study in Plastic Education concluded that a reusable bottle — whether glass, aluminum, or plastic — almost always becomes more sustainable than a comparable single-use bottle after a modest number of reuses. In many practical day-to-day scenarios (e.g., using the same bottle daily), the break-even point is surpassedquickly (within weeks to months of regular use).