INTRO TO BEER CARBONATION & WHY GETTING IT RIGHT IS SO IMPORTANT

       We don't list Carbon Dioxide [CO2] as an ingredient in our beer, but one could argue that we should.  The primary reason we don't, is because CO2 occurs in Beer, as a natural by-product of the brewing process.  The reason that some of us feel it should be included, is because modern brewing, kegging, and packaging methods cause carbonation loss.  The lost CO2 is forcibly reintroduced, during the finishing process of the beer.  If the beer is served from a keg, CO2 is also introduced, again, during dispense.  Finally, in the case of Nitrogenous beers such as Guinness, Boddington's, Old Speckled Hen, and numerous others, we also add Nitrogen gas, as way to lighten the mouth feel of these Low Carbonation Brews.  The reason I would advocate for listing gasses as ingredients, is to also show customers that only 1 or 2 gasses are supposed to be there, and lends credibility to quality advocates.  These Gasses effect flavour and presentation. When the additions of gasses, which are not part of the recipe,  cause issues, it will help Brewers and Quality Advocates, such as good Technicians and Cicerone's, bolster our cause.  We can say, "The beer is not the issue, your crappy gas mix, or air blend, is the issue".  

     For those of you not yet versed in the Beer and CO2 relationship, there are a few things we need to touch on:

1. MEASURING CONTENT
1. There are several measurements of CO2 content, but the one most widely used in North America, especially when it comes to keg beer,  is "Volumes of CO2".  
2. MAINTAINING CONTENT:
1. CO2 does not want to stay in solution.  At least, not in the amounts we want, in our beers.  We manage to keep it there, by keeping it confined, under pressure, and keeping it cold.  And by cold, I mean below 4°c/40°f.  The temps at which many of us enjoy our ales are actually, too warm for successful dispense.
2. As we remove beer from a keg, we have to replace it with pressurized gas, or some of the CO2 will come out of solution and the beer will taste "flat".  
3. Remember that CO2 is a HUGE part of beer flavour.  The popping bubbles increase aroma.  Sense of smell accounts for about half of the flavour experience.  If you don't believe me, the next time you have a beer, pinch your nose and take a sip.  CO2 also adds a sharp, vaguely smokey, bitterness, and as the bubbles bloom on your tongue, they serve to balance the richest and sweetest notes, which might, otherwise, overwhelm the profile.  Think about how much sweeter a Soda seems, when it goes flat.  Think about how carbonated water tastes, vs. still water, and how, even if after it goes flat, the flavour lingers. The right amount of CO2 is needed to balance a beer's flavour correctly. 
3. BALANCE, BALANCE, BALANCE: 
1. Sometimes, the correct pressure for maintaining carbonation is all that is required to dispense the beer.  Such beer systems are usually very short, most commonly serving right through the cooler wall; AKA Direct Draw.
2. Most system, however, require more pressure to keep the beer in solution as it travels toward the faucet. Mechanical Pumps, or blends of gasses, are used to provide this extra boost. If one simply turns up the CO2, it will over-carbonate the beer, be difficult to pour, taste sharp, and bloat the consumer. A bloated customer wont order a second beer, appetizers, a desert, and worst of all is less likely to go home with cans or a Growler.  💔😢
4. FOREIGN GASSES:
1. Often, the method used to augment pressure is Blended gas, most commonly, Nitrogen(N2).  At the lower pressures required for non-Nitrogenous beers, Nitrogen will not, to any great degree, go into solution.  What little that may, will boil out upon dispense, with infinitesimal effect on flavour.  Nitrogen's inert characteristics further safeguard the chemistry, which to this point, serves in keeping active yeast and bacterium dormant.  This blend is commonly created on site,  with a Blender that is fed by compressed gas cylinders, or by a Nitrogen harvester/generator. Beer pumps are usually driven by gas or compressed air.  This Air is clean and dry, and never touches the beer.  If need be, electric pumps are also available.
2. In days past, and even today, on rare and sorrowful occasions, people use compressed air mixes, to prvide the extra pressure.  This ruins the beer.  Oxygen is horrific for your beer! The helpful yeast and bacteria that created your beer are, at this point, either dead and preserved, or comatose.  The comatose ones wake up, and start brewing again.  At this point, since yeast are weaker and fewer, they begin to loose dominance.  They are overtaken by oxidizing bacteria.
3. WARNING: NOT FOR THE QUEASY. If you have a weak stomach, trust that air and oxygen are bad for beer, and move on to Nitrogenous beers.  Air is the friend of oxygenating agents such as Lactobacillus acidophilus, and any of the 10 genera from the Acetobacteraceae family of Bacteria.  Pediococcus and maybe even Megasphaera, like  Clostridium (less common in beer, but the one that will cause food poisoning)or Pectinatus are likely present, as well.  These Bacteria create diacetyl lactic acids, acetic acid[vinegar] butyric acid[bile], methane, and hydrogen sulfide[swamp/sewer gas].  The smells produced are as if someone were pickling eggs, in a busy, 3rd-world brothel.  The flavour addition, for me,  is a cross between Eggnog and over-cooked, hard-boiled egg, with a bit of preserved lemon and butter in the finish, all the while, vaguely whiffing of vomit. 
5. NITROGENOUS BEERS.
1. This family of beers are commonly referred to as Stouts, but this is not really correct.  While many Nitro Beers are Stout Ales, some are not.  Two popular examples would be Boddington's and Old Speckled Hen.    Furthermore, not all Stout Ales are Nitrogenous.  Guinness makes a non-nitrogenous Extra-Stout, which is about 2.5 Volumes, to my recollection. "Nitros" are, generally Ales, but Nitro lagers have begun to make an appearance.
2. One common factor of Nitro's is that they are lower in CO2 content, and are usually malty, nutty, chocolaty, and/or seem heavier on the bitters.  Even though they are often lighter in sugars, they are unfairly accused of being "heavy", as the reduced CO2 content makes for a denser mouth feel.  This is where Nitrogen saves they day.  The fine bubbles in the solution serve to lighten the mouth feel, and draw out the sweeter and creamier notes, serving to offset and balance the bitters.  If carbonated at the level of a regular ale or lager, the bitterness would be too intense for most drinkers.  These beers are designed for, and finished with Nitrogen, and are crippled without it.  Whenever possible, blend the gas on-site, by Blender box, generator/blender, or in a cylinder equipped with a self-mixing valve.   
6. RESPONSIBILITY,  OWNERSHIP & AMBASSADORSHIP.
1. My responsibility: As an Equipment Technician and System Designer, my first responsibility is to the Beer.  I Identify with Lord Varys from Game of thrones, who answered the inquiry as to who he serves, by saying "I serve The Realm.  Somebody aught to."  Well I act in service to the Beer.  We all aught to.  To be more specific, I do my utmost to ensure that the beer in your glass meets the expectation of the Brewer's intention.  All of my choices are made to protect the beer, first.  My second responsibility is to Practical Operation and Maintenance, over the 5-15 year life of the assorted components.  My 3rd Desire is to blend with, pay homage to, or enhance the aesthetic and culture of the location.  Just remember, When it comes to Front House Aesthetic, the most attractive, valuable thing you can put in view of potential customers is a smiling and happy patron, that wants you to succeed.  A pretty beer tower is a Nice to have, not a need to have.
2. Taking ownership: Remember that if you touch it, or can't prove you didn't, It belongs to you.  Leave everything better than you found it.  If there is a dangerous situation, you really should insist it be corrected.  If the owner refuses, document it, and report it.  If somebody is injured or killed by something that you could have corrected or reported, I don't imagine it's going to sit well with you.  Even if you or your employer is unmoved by concerned for your fellow humans, there are still possible financial and criminal prosecutions that may result from an investigation. Keep good records, takes pictures, and report it to the appropriate authorities.
3. AMBASSADORSHIP:. Confession, I don't care for sours, it isn't often that I find a lager or Pilsner, I actually enjoy.  Then again, I enjoy some paint peeling porters, and some multi-layered belgians that many would wrinkle their nose at. I also like Radlers and Shandy.  There! I've said it. Can we just move on, please? What I really want to illustrate is, what a "good" beer is, is subjective. To each,  their own. Just because I don't care for it, doesn't mean it's bad. It only means that it is not to my taste. Our community is smaller than it seems. It is also a community full of people, who for the most part, are kind and generous people. It is very easy to make friends. It is also pretty easy to gain a reputation of being an asshole. And once you have managed to earn such a reputation, amongst such a kind and accepting community, it is awfully hard to change that perception. This is an industry, that if you take care of everything you touch, these people will take notice, and in turn, take care of you. I'm going to paraphrase one of my favorite authors, Robert A Heinlein *"Moving parts, in rubbing contact, require lubrication to prevent wear. Formal politeness, honorifics, and manners serve to provide lubrication where society rubs together. Unfortunately, there are often entitled, ignorant, often poorly read, or untraveled people who ignore the most basic manners.  They bypass and dismiss any politeness or honorific, formal or otherwise, espousing them as empty, meaningless, beneath them, or a waste of time.  In actuality, this disregard is hurling sand into a machinery, which doesn't work too well, to begin with."*

So now, with this basic understanding of beer gas, and this roadmap to enlightenment before you, go forth. I send you off with the words which see my child to school, in the Before Times:

Be safe. Be kind. Have fun. 

Dan Broaddus

*Paraphrased from Time Enough For Love and The Notebooks of Lazurus Long. By Robert A. Heinlein.