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**choosybeggar** · 03-13-2013, 11:12 PM

So I checked out the Party Pig website:

Quote:

The package requires no CO2 tanks or cartridges because it uses a self-inflating pressure pouch. As beer is dispensed from the PET plastic bottle through an attached push-button valve, the internal pressure pouch expands and maintains a constant 15-20 pounds per square inch of pressure. This is accomplished by combining citric acid and bicarbonate of soda in a controlled manner to produce CO2 gas, which remains inside the pressure pouch and does not come in contact with the beer.

Seems like just the ticket. Thanks.

Mike37 · 03-13-2013, 11:23 PM

I see the party pig working just fine as long as the beer itself can be primed below 1.5 volumes.

Not saying it would be difficult, just that it's the key to this all working.

techbrewie · 03-13-2013, 11:38 PM

+1 to marketing for all of the misinformation out there.

At serving pressures (10-12psi for regular taps, 30psi for stout taps), a negligible amount of N is dissolved into the liquid. Beer is and always has been carbed with Co2, regardless of style or carbing method. This is because Co2 is the gas naturally created by yeast when bottling carbing.

The creamy head is a result of smaller Co2 bubbles created by the beer being forced through the restrictor plate of a stout tap. The smaller the surface area of any surface, the more stable it is. There are some physics equations that prove it somewhere, but im not going to get that sciency on you.

Now to push the beer through the restrictor plate you need a psi of around 30 psi (varying depending on the balance of your system) to get an acceptable rate of flow. If did it with just Co2, too much would be absorbed into your beer resulting in over carbed beer. This is corrected by mixing the Co2 with a gas that cannot be dissolved in liquid at those pressures(i.e. argon, nitrogen).

The sole purpose of nitrogen is to prevent over carbonation of your beer at the pressure required to push beer through the stout tap to create the desired mouthfeel and head for that style of beer.

When I get a little time I would be more that happy to post all of the equations and physics principles that support this, butchphr it might be a while before I can get to it. Nitrogen Sounds fancy and has been used as a catase by breweries (who should / do know better) to market their stouts and some porters.

Even if a beer was pushed on pure nitro across a long/thick enough beer line to support the pressures it would require to dissolve in beer, upon leaving the tap all of the nitro would surge out of the beer leaving you with nothing but foam.

mattd2 · 03-14-2013, 12:25 AM

Quote:

Originally Posted by techbrewie

...Now to push the beer through the restrictor plate you need a psi of around 30 psi (varying depending on the balance of your system) to get an acceptable rate of flow. If did it with just Co2, too much would be absorbed into your beer resulting in over carbed beer. This is corrected by mixing the Co2 with a gas that cannot be dissolved in liquid at those pressures(i.e. argon, nitrogen)...

Is that 30 PSI at the keg or tap? From what I have seen it is at the keg and I have always had a theory the beergas might not even be needed for a "normal" homebrew setup. If the keg is hooked up with a short section of 1/4"/5/8" beerline then the normal ~15psi drop would not be present and you could serv on pure CO2 at a lower pressure and suitable temp to get the required pressure at the stout tap.

Mike37 · 03-14-2013, 12:45 AM

Quote:

Originally Posted by mattd2

Is that 30 PSI at the keg or tap? From what I have seen it is at the keg and I have always had a theory the beergas might not even be needed for a "normal" homebrew setup. If the keg is hooked up with a short section of 1/4"/5/8" beerline then the normal ~15psi drop would not be present and you could serv on pure CO2 at a lower pressure and suitable temp to get the required pressure at the stout tap.

That's 30 psi for a decently quick pour. 10 psi of co2 (or nitro, beer gas, etc.) will push beer through a short line and a stout faucet just fine, albeit slower than your typical nitro pour at 30 psi.

I have my keg set up exactly this way right now. At my keg's temperature, I can leave the regulator set at 8-10 and not worry about over carbonation.

techbrewie · 03-14-2013, 12:53 AM

that is a ballpark psi setting at the regulator. There could be a variance of + - 1-2 psi based on how you have your lines balanced (line diameter, line length, height distance from keg top to tap, carb volume etc.). Beer gas is not needed at all on a normal homebrew setup. It is only needed when you implement a stout tap.

As for your theory, it definitely merits an experiment. either it works or you end up with pure foam. Assuming it worked, you may run in to the problem of not having enough line to reach your taps if you go too short :-P.

Most bars run everything on beer gas for the sake of using 1 gas and being able to push all types of beer. for me there is no place in town that fills beer gas, so no stout tap for me :-(

**Pratzie** · 03-14-2013, 01:00 AM

I was lead to believe that the Nitro is just to assist pushing the beer thru that restrictor plate in the faucet. That the pressure has to be greater then the CO2 alone but that the bubbles themselves are still CO2 that has been pushed thru the plate and has that cascading effect.

Guess im jumping on the pile here, sorry for not reading all the posts firsts

mattd2 · 03-14-2013, 01:13 AM

Quote:

Originally Posted by techbrewie

...Beer gas is not needed at all on a normal homebrew setup. It is only needed when you implement a stout tap.

As for your theory, it definitely merits an experiment. either it works or you end up with pure foam. Assuming it worked, you may run in to the problem of not having enough line to reach your taps if you go too short :-P...

Sorry I meant normal homebrew setup with a stout tap. Looks like someone (Mike37) did experiement.

Quote:

Originally Posted by Mike37

That's 30 psi for a decently quick pour. 10 psi of co2 (or nitro, beer gas, etc.) will push beer through a short line and a stout faucet just fine, albeit slower than your typical nitro pour at 30 psi.

I have my keg set up exactly this way right now. At my keg's temperature, I can leave the regulator set at 8-10 and not worry about over carbonation.

Thanks Mike, I have been wondering this for a while but don't have the cash to invest in a stout tap! now just to get this method out to more people!

branCHEs · 05-07-2013, 03:57 AM

So i think its fair to say that the debate is over. Nitro provides the pressure to push the beer through the restricter plate in a reasonable time with out over carbonating the beer. The actual bubbles are 100% CO2.

My only question: how does Guinness manage to achieve this cascading effect from their can? I believe Boddingtons English Pub Ale also manages to achieve this affect. I know the both have a little plastic ball inside of the can. I have been told that the balls are filled with nitrous and releases upon opening can.

**choosybeggar** · 05-07-2013, 05:46 AM

The devices generate a turbulent stream of beer on opening the can. In the sealed can, they are beer filled and at the same pressure as the contents of the can (well above atmospheric). Opening the can produces a dramatic pressure drop but the only way to relieve pressure within the widget is for gas and beer to shoot out of it's small hole, generating turbulent flow and CO2 foam.