Regulator problem

Did you vent the pressure after turning down the regulator? Otherwise the 30 psi you already put in there has no where to go.

 

It would release some aroma. But if you don't, it may take a while for your pressure to come down (as some of the headspace CO2 is slowly absorbed by the beer).

 

It will release some of it, but that is the price for fast force carbing your beer. I prefer the slower more precise method. Keg on Sunday and apply appropriate pressure for style/temp then by Friday its ready to drink. Don't fret, there will still be plenty of hop aroma left after venting.

 

The slower you carbonate the more time the CO2 molecules have to hydrate. You can get nice, tight, creamy bubbles that more closely resemble champagne than Coca Cola bubbles from a fountain machine. Slow, gentle bubbles also don't scrub your beer. You can lose esters and aromas when you blast it with air too quickly. Lastly, overcarbonating your beer or even just quickly carbonating can result in the formation of excess carbonic acid (an organic byproduct of carbonation), which can be harsh, bitter, and unpleasant.

In commercial brewing, and more advanced homebrew setups, it's ideal to use a sparging stone to diffuse the CO2 into the solution inside the keg. However, this is overkill for a small setup unless you're a freak to detail. There is a fantastic article by Dave Maheen regarding commercial level carbonation, which isn't entirely applicable at the homebrew level, but is worth reading anyway: http://www.meheen.com/wp-content/uploads/2014/05/meheen-carbonation-demystified.pdf

Essentially, the main takeaways for a home setup is that desired carbonation level and temperature are your two main factors in determining your regulator pressure. The colder your beer is the less CO2 you have to push into your vessel to diffuse. How quickly the CO2 diffuses into solution largely has to do with your protein levels and the chemical composition of your beer.

If you want to accelerate the process, you can put a liquid disconnect on your regulator and connect it to the long out dip tube at about 3-4 psi. This will bubble the CO2 through the beer rather than fill the head space and push down into it. Bubbling through your beer is how almost every commercial brewery in the world force carbonates. Every half hour turn the regulator up by 1 psi until you reach the necessary PSI to achieve your desired dissolved CO2. BIG DISCLAIMER: turn your CO2 on before you connect your quick disconnect, and disconnect it before you turn your tank off! Otherwise you'll have beer shooting back up your line.

For example: your beer is 35 degrees and you want to take it to 2.6 volumes (a good target). There is roughly 28 inches of beer above your dip tube so you want to add 1 psi to the recommended PSI in your Carbonation Level Chart. This is because the weight of the beer is pushing against the CO2 flowing from your dip tube. At 35 degrees it takes 11 psi to reach 2.6 volumes so you would slowly nudge up your regulator over the course of the day until it reached a setting of 12 PSI.

You don't have to do this. It's called step up carbonation, and limits the amount that you scrub the esters and aromas out of your beer, makes tighter bubbles, and is a lot slower than blast carbonating while venting the keg. I find it to be a happy medium between the harsh soda fountain bubbles from in line carbonation and beautiful, tight, creamy champagne bubbles.

The same basic principles apply if you simply want to push into the head space of the keg, it just takes a little longer for the CO2 to diffuse. Last week, I had a pale in my fridge at 41 degrees, and I simply hooked up my gas in disconnect and set it to 14 PSI and went away for a couple of days. When I came back, I had a perfectly carbonated beer (I actually own a zahm and nagel - a CO2 measuring device, from my days in commercial brewing, and measured it - it was right at 2.6 volumes). Really, the only reason to go in through the liquid dip tube is to accelerate the process without compromising the beer. But all of us have been there, with an uncarbonated beer on Friday and a party on Saturday, and that's the best way to cut a 2-5 day process down to 1-2 without potentially changing the aroma and flavor profile of your beer.

Whatever your process, always remember that there is more going on when you carbonate than simple CO2 addition. You are shifting the acid, the mouthfeel, and the perception (or even presence) of esters and phenols in your beer. It is a vital step, and rushing it after putting so many careful hours into brewing and fermenting your beer seems crazy to me. You can be the best brewer and fermenter in the world, and if you don't know how to carbonate and bottle/keg properly, it can completely nullify what would have been a spectacular beer.

 

Not that I would use this method - if I want a beer ready for an event, I plan ahead - but I'd advise anyone contemplating it to make sure they have a check valve between the keg and the regulator, in case the gas runs out. Or in case a leak develops at the keg/regulator interface.

 

Thanks, forgot to mention the check valve. I do generally use a check valve as a precaution, but just keep in mind that most check valves are not always 100% effective when the keg pushes back against it. That's a lot of pressure for a check valve to handle if the beer is well on its way to being carbonated. I have a check valve that can deal with that kind of pressure (I modified a beer nut/sanke check valve to function as an in-line-one-way but the plastic ones that most homebrew supply shops carry can only actually handle 1-2 bars in my experience. Definitely a good measure is to always start with a full tank of CO2 and make sure you don't have any leaks.

Lastly, the real benefit of this method of carbonation means that you don't have to shake your keg to get it to diffuse into solution, which is pretty sweet, even if you do ALWAYS plan ahead.