Beer Gun question

[Kernel32]

Just ordered a beer gun because I'm sick of bottle conditioning being inaccurate at best. (That's another post for a another time.)

Initially I was intrigued by the two "advantages" of the beer gun. 1) The ability to bottle force carbonated beer and 2) Purging all air from the bottle to avoid oxidation and off tastes.

The first part I have no problem with and that's why I ordered the device. The 2nd aspect though, upon closer contemplation seems like total BS.

To start with, you have a bottle, empty of everything but air. You insert the beer gun and give it a blast of CO2 to expel the air. At this point you have an open bottle of CO2 with a beer gun stuck in it.

Next you fill the bottle. As the level of the beer rises, it pushes the CO2 out the top of the bottle. CO2 is heavier than air. As is it expelled out of the bottle, it will flow over the sides of the bottle and down the outside and/or dissipate into the atmosphere. Once filled, you're left with a bottle full of beer with a beer gun stuck in it.

Here is where the story of the beer gun breaks down for me. At this point, you remove the beer gun. As you remove the tube, gas is then pulled back into the neck of the bottle as the level of beer goes down equal to the volume of the beer gun's filler tube. Unless I'm mistaken, this gas is essentially just air. The very thing you purged with the blast of CO2 to begin with.

How does this leave you with anything different than if you'd just filled the original empty bottle? Is there a point in purging the bottle first? It seems like some vast conspiracy to force you to waste CO2, spend more $$ to refill tanks faster and contribute to global warming. (I might be exaggerating on that last little bit.)

Seriously though, is there something I'm missing?

 

[Jwin]

In short, if you are filling with carbed beer, you should have a little foam(if you technique is sound) which is mostly just beer and co2 that will push the air out. You cap on the foam.
If you are bottle conditioning/carbing, you can add a tap of co2 just as the gun exits the bottle and drop a cap on.

 

[kh54s10]

Well the difference, if the neck is not filled with foam, is that the entire time filling a non purged bottle the beer is in contact with air. With purging you get a very little bit of air back in when removing the gun.

To me either purging or not purging is of no real consequence. When I bottle from the keg I use a tube from the faucet into the bottle that is not purged. These beers are going to be drunk in no more than a couple of days so oxidation is not really a concern to me. Besides that these beers are usually gifts to friends. I don't drink them.

 

[Sadu]

The reason for purging is so the beer is transferred into a mostly co2 environment. So any oxygen damage from splashing is minimised.

 

[eric19312]

Pull the wand out slowly as you reach the neck. No suckback. Cap on foam. No question the beergun enables bottling with reduced amount of oxygen vs picnic tap plus tube. Not sure if it's actually better than properly refermented in the bottle, for beers you want to age I think that is still best way to go.

 

[govner1]

Just ordered a beer gun because I'm sick of bottle conditioning being inaccurate at best. (That's another post for a another time.)

Initially I was intrigued by the two "advantages" of the beer gun. 1) The ability to bottle force carbonated beer and 2) Purging all air from the bottle to avoid oxidation and off tastes.

The first part I have no problem with and that's why I ordered the device. The 2nd aspect though, upon closer contemplation seems like total BS.

To start with, you have a bottle, empty of everything but air. You insert the beer gun and give it a blast of CO2 to expel the air. At this point you have an open bottle of CO2 with a beer gun stuck in it.

Next you fill the bottle. As the level of the beer rises, it pushes the CO2 out the top of the bottle. CO2 is heavier than air. As is it expelled out of the bottle, it will flow over the sides of the bottle and down the outside and/or dissipate into the atmosphere. Once filled, you're left with a bottle full of beer with a beer gun stuck in it.

Here is where the story of the beer gun breaks down for me. At this point, you remove the beer gun. As you remove the tube, gas is then pulled back into the neck of the bottle as the level of beer goes down equal to the volume of the beer gun's filler tube. Unless I'm mistaken, this gas is essentially just air. The very thing you purged with the blast of CO2 to begin with.

How does this leave you with anything different than if you'd just filled the original empty bottle? Is there a point in purging the bottle first? It seems like some vast conspiracy to force you to waste CO2, spend more $$ to refill tanks faster and contribute to global warming. (I might be exaggerating on that last little bit.)

Seriously though, is there something I'm missing?

The last "step" is to give a brief burst of CO2 into the top of your filled bottle before capping.