Because "flat beer sucks."
These days, the growler is the container of choice for smaller craft breweries looking to get new beers out to customers and into their homes. Growlers are big enough to hold several servings to share, but small enough for easy transport.
But sometimes, it's just not possible to finish that new brew in one sitting, and your leftovers end up sad and flat in the back of the fridge. The TapIt Cap offers a solution, turning your growler into the mini-est of kegs. As the manufacturers explain, "drinking a growler of good beer should not be a race against time and inebriation." Each kit comes with one cap, a CO2 dispenser, and a disposable, food-grade CO2 canister. It should fit on most screw-top growlers, and, if used properly, can be used on five bottles before needing replacement. Drink on!
TapIt Cap, $45 at TapItCap.com