This may be a topic that only a few of you beer fans out there may be familiar with. If your primary beer of choice is an American Lager, or even an IPA, you may never enter the world of nitrogenization.
What is nitrogenization, you ask? Simply put, it’s the practice of replacing Nitrogen in place of Carbon Dioxide to the taps of a draft beer. Well, that’s not entirely true. It’s really a mixture of nitrogen and carbon dioxide. The ratio may vary from beer to beer, bar to bar, or even from country to country. We here in the States typically run a mixture of Guinness around 70% nitrogen to 30% CO2. In Ireland, that ratio goes up to 80/20. This is one reason why Guinness tastes different in Dublin than it does in Seattle.
But what does nitrogenization bring to the tap that regular CO2 does not? Let me quote from Guinness Master Brewer Fergal Murray, as quoted in Bill Yenne’s book Guinness: The 250 Year Quest for the Perfect Pint:
“The bubbles float to the top, surrounded by the surface tension of the beer. That’s why they don’t dissipate as as fast as carbon dioxide bubbles that occur naturally in all beer. The carbon dioxide bubbles dissipate because there is less surface tension to hold them in place. The nitrogen bubbles don’t dissipate. The nitrogen can’t escape because the protein-carbohydrate mix that holds the beer together is so strong.”
Now most consumers will not notice a beers surface tension let alone it’s protein-carbohydrate mix. What they will notice is a thick head with very fine bubbles that seem to last forever. This head also adds to the “creamy” mouthfeel of the beers that use a nitrogen tap.
Many people mistakenly assume that this characteristic is specific to Guinness. This is not true, as several beers in the market now recommend a nitrogen tap if the bar can get it. Guinness just happens to be the most widely known.
Are there drawbacks with using a nitrogen tap? Absolutely. These beers can and do fall flat rather quickly. Additionally, many people start believing that nitrogenization should be standard for a specific type of beer (often stout, because of Guinness). Nothing could be further from the truth, as there are many good to great stouts that hold up quite well with C02 only taps. Nitrogenization should be considered a company-specific option rather than a style-specific one.