"Bar Month" at OnMilwaukee.com is back for another round – brought to you by Aperol, Pinnacle, Jameson, Fireball, Red Stag and Avion. The whole month of February, we're serving up intoxicatingly fun articles on bars and clubs – including guides, the latest trends, bar reviews and more. Grab a designated driver and dive in!

Recently, OnMilwaukee.com reported on the Riverwest Filling Station, a new growler bar that opened at 701 E. Keefe Ave. The owners, Bryan Atinsky and Allen and Kari Church – with the help of Ald. Nik Kovac – had the law changed in Milwaukee so bars could sell growlers of beer.

Prior to the 2012 law change, it was only legal for brew pubs to sell growlers. With the new law in place, more and more local bars will offer growlers and some drinkers might not fully comprehend the pros and cons of growler drinking.

For starters, a growler is a 64-ounce container that's usually ceramic or glass with a screw-on or hinged cap and a loop-shaped handle. Growlers allow customers to purchase tap / craft beer to go. The popularity of craft beer has made growlers more coveted among consumers in recent years.

The term "growler" is believed to have originated in the late 19th century when fresh beer was carried from the local pub to a person's home by a small galvanized pail. The sound that the CO2 made when it escaped from the container supposedly made a growling noise.

Charlie and Ernie Otto of the Idaho-based Grand Teton Brewing Company in 1989 invented the modern growler.

Stubby's Gastrogrub & Beer Bar, 2060 N. Humboldt Blvd., started selling growlers of beer in late 2012. Stubby's has 53 beers on tap and almost all of them are available to go in growlers. Occasionally,  the pub will receive a very small batch of a particular beer – around five gallons – and won't offer it in anything larger than a glass.

For batches that are slightly larger, co-owners Brian Zarletti and Bradley Todd limit growler sales to 10. Such was the case recently with Zombie Dust, a rare pale ale made by Three Floyds Brewing Company in Munster, Ind.

At Stubby's, growler containers cost $5 and can be reused repeatedly. The bartenders employ a disinfectant used by home brewers to sanitize before refilling. A customer does not have to use a growler purchased on site to get it filled, as long as it's 64 ounces, which is about the equivalent of four pints.

"Growlers let people take home and try beer that's not for sale in a liquor store," says Todd.

Prices for growlers range depending on the beer. Many are around $12, making growlers an affordable option for craft beer consumption.

Growlers must be sealed upon purchase and cannot be opened until the person reaches his or her home or destination. They are ideal for bringing to a house or dinner party or to share with another person or two while watching a game or a movie.

"We're a neighborhood place, so a lot of our customers appreciate being able to grab a growler and head back to their couch," says Todd.

Once open, growlers are best when consumed immediately. They can be stored in the fridge for a day or two, but the quality will decrease.

Although usually filled with fresh craft beer, growlers can also be filled with macro-brewery beer or cider.

At Stubby's the most popular growler beers are the house beers, a hoppy brown ale called Godfather Brown (named for James Brown) and an amber saison (sometimes called a "farmhouse ale") called Slapshot Saison. Both are brewed by The Milwaukee Brewing Company with input from Todd and Zarletti.

Will growler sales decrease the number of bar patrons? Todd doesn't think so.

"If people are going to drink at home, they're going to drink at home," he says. "And if they want the bar setting, they will pick the bar setting. We're available for both."