With craft beer in the midst of a boom, there are many trends and things to watch. When all is said and done, chief among them in 2010 may be the can.

[8/24 Update: Check out the full list of more than 75 craft breweries that can.]

[5/12 Update: Still in the process of researching this but there now appears to be not just 60 or 70 but over 79 breweries with at least one brand in cans. That is a 60% increase over the Brewers Association list posted in September. I hope to post a complete list next week.]

Yes, craft breweries have been canning beer since 2001 when Cask Brewing Systems developed a new system for small breweries. Oskar Blues was the first to use it. Capital Brewery claims that it introduced its Amber Ale in cans back in 1997 [any earlier references?]. MacTarnahan’s Brewing was also canning beer in the late 90s. There has been a surge in craft cans in recent years though, and in 2010, they have gained a significant amount of attention, even from mainstream media outlets.

Nowhere is the can craze bigger than in Colorado. The Longmont Ledger featured cans in the Centennial State last month. Setting up a canning line for the first time this summer is Avery Brewing who will put some of their core products as well as a new beer in cans. The Ledger quoted Adam Avery as saying the new brew would be a “super, extremely hoppy” pilsner. A brewery rep estimates late June or July as the timeframe for their debut.

Also entering the mix is Boulder Brewing whose Hazed and Infused cans are hitting the market for the first time this month (see pic below). They join a number of other Colorado brewers like Oskar Blues, New Belgium, Wynkoop, Ska Brewing, Breckenridge and Upslope Brewing.

The same article notes that Boulder-based Twisted Pine Brewing is giving serious thought to joining its Colorado brethren.

Elsewhere, 7 Seas Brewing became the first craft brewery to can in Washington last month. This fall, Baxter Brewing will become the first to do so in Maine. Within the past two weeks, The Brewer’s Art and Pyramid Breweries both announced entry into the can market.

Just how many craft breweries can? The Brewers’ Association reported back in September that 52 craft breweries offered at least one of their brands in cans though that number has since increased past 70 breweries.

Not everyone sees that as a good thing. Some still contend that they prefer beer to be poured from a bottle. A post mentioning a brewery was offering a new beer in cans on a popular Italian beer blog has garnered over 120 comments, many of which partake in the old bottle vs. can debate.

No matter where you stand on the issue, know that the can movement is not slowing down anytime soon. By the end of 2011, expect there to be at least 100 craft breweries having offered beer in a can in the past year.