If you’ve ever been to a pub that serves “real” Guinness, you’ll notice that the bubbles seem to cascade DOWN the glass and the head has very small bubbles, unlike “normal” beer. What you’re witnessing is beer being poured from a nitrogen tap.
Nitrogen is insoluble in water, and produces much smaller bubbles and a very creamy mouth feel. But you wouldn’t want flat beer with a great head, so the typical gas is 25% CO2 (for “normal” bubbles) and 75% nitrogen under higher pressure than a typical CO2 system. In a taproom, the beer is forced through a plate with tiny holes to accentuate the head. There’s nothing better than seeing that firm, white head on top of a dark, dark beer!
If you’re drinking at home and want to try a nitrogenated beer, head down to The Beer Run and pick up some Left Hand Mild Stout Nitro, or Left Hand Sawtooth Nitro. The experience is a little different drinking nitro beers from a bottle, but the flavor and feel will still be unique.
Check out the review of the Left Hand Milk Stout here.