Joe Schiraldi is Vice President of Brewing Operations at Left Hand Brewing Company in Longmont, Colorado. In 2011 Left Hand was the first American craft brewery to release a nitrogen version of a bottled beer. The brewery now bottles three nitrogen beers.
There are obviously pros and cons with nitro. From a visual perspective, a nitrogen head really captures that vision of what head on a beer should look like. It’s big, frothy and displays a great texture. The cascading bubbles are certainly a delight to observe and serve as nice foreplay before diving into that first sip. I find these things to be important. The mouthfeel is smooth, pleasant and unencumbered by CO2 acidity and bite. N2 allows your palate to discover flavor nuances otherwise hidden by CO2 sensations.
Aromatically I think nitrogen beers change the ground rules a bit. CO2 bubbles have a tendency to burst and that can carry volatiles very effectively to your sense of smell. The more aromatically centric a beer is the less I believe it lends itself to nitrogen presentations although I try to avoid speaking in absolutes.
The wort used for each of the beers we serve with nitro is the same and is treated the same from a process standpoint as their CO2 counterparts. The only recipe difference is the gas blend. N2 beers are really an N2/CO2 blend. Dissolved CO2 is naturally present after fermentation even if you let it blow off. You need to be cognizant of this residual CO2. Nothing messes up an N2 pour like out of spec CO2 concentrations.
There absolutely are nuances of flavor between beers carbonated with N2 as opposed to CO2, and I’m not sure it could be possible to get these two versions of beer to taste the same. For instance, our Milk Stout displays a distinct balance of coffee and chocolate notes. On my palate the Milk Stout Nitro throws more chocolate aromas at me whereas the CO2 version has a more pronounced coffee element. Nitrogen vs. CO2 without question shifts that balance around. I think the Sawtooth on nitrogen has a softer more subtle hop character but at the same time there are some delightful cereal and toffee flavors that I feel get enhanced. I always look at these things in terms of each flavor or aromatic note fighting to be recognized; it’s clawing its way to the consumer’s senses.
When it comes to big beers like our Wake Up Dead Nitro, which we age for months before we release it for package through our taste panel, you really have to be respectful of what nitrogen does to your ability to taste immaturity. I feel N2 is less forgiving in that regard than CO2 is once you get it in the bottle.
For homebrewers, keep it clean, keep it cold and use the right gas mix for dispense. The right gas mix will settle anything down over a rather short period of time as the keg equilibrates. Keep an eye on and control residual dissolved CO2 after primary; this has a huge effect on pourability. It’s easier and better for your beer to add CO2 rather than having to take it out. However, if you are trying to serve your homebrewed stout to your friends you have a little leeway. After all, no matter how bad you screw up the gas mix initially, once you tap it on a gas blend the mix changes and reaches equilibrium to its new environment rather quickly.
While working as an IT Administrator, Mike Dorneker started homebrewing and fell in love with the process. He graduated from the associate program at Siebel Institute of Tech-nology in 2010 and interned at Metropolitan Brewing before being hired in 2011 as the Master Brewer at Lake Bluff Brewing Company, in Lake Bluff, Illinois. His barrel-aged imperial stout and robust porter have won medals at the United States Beer Open.
Nitro beers add another element of complexity to the beer, giving the brewer a whole new class of beers to play with. Nitrogen gives a more full, creamy body and mouthfeel. That said, with nitrogenated beers there is less perceived hop bitterness and aroma, and I have seen instances where nitro can change a beer from good to subpar.
We serve one of almost every beer we make on nitrogen without making any adjustments to the recipe or brewing technique because you just never know until you try it. We have tried everything from our golden ale all the way to our Imperial IPA. Some worked better than others. I was shocked with how well Skull and Bones, our double pale ale, turned out on nitro. It’s a fairly bitter beer but with a nice malty backbone. The nitro really brought out the malty side of the beer and muted the bitterness just enough, making for a delicious surprise. Alternatively, we tried our Honey Badger Golden Ale, which is more bitter than most golden ales and is balanced by sweetness from the honey. The nitro version muted the bitterness and erased the sweetness, leaving a watery, plain, nothing beer. Still, it’s fun to see what the beers will taste like side-by-side, nitro vs. CO2.
The brewpub has a dual regulator system, one for nitrogenating and one for serving. This way I can nitrogenate a single keg and always have one on tap. I can take as many kegs per batch as I want for nitro and carbonate the rest. This can easily be replicated on a small scale for homebrewers.
Since we serve the same batch on both nitro and CO2 we don’t alter the recipes, but if you wanted you could do things like give a recipe more of a malty body/finish to be accentuated by the nitro, or change your mash temperature to give you more non-fermented sugars for a beer that has more body. That extra body will result in a fuller, creamier nitro beer.