Question about Beer Gun or any like device, really

[303Dan]

Hey Everyone,

I have sort of a broad question about using a Blichmann BeerGun, or really any type of device that is used for bottling from a keg:

A common thread to all these types of devices seems to be that you want to lower the serving pressure way down to push the beer as slowly as possible into the bottle to avoid foaming. My issue is that as soon as I lower my serving pressure, I start seeing CO2 coming out of solution in the beer lines, whether I'm trying to pour out the faucet, or use any sort of bottle filling mechanism. From my understanding, that is somewhat unavoidable due to the imbalance that's being created between the carb level of the beer and not enough pressure on top to balance it. To me, that would indicate that no matter what, my bottled beer is going to have less carbonation than a beer poured out of my faucet under appropriate serving pressure. Is that just "the cost of doing business" when bottling this way?

To me, the reason I started kegging in the first place is because I disliked bottling. The only reason I want to bottle at all out of the keg is to take a few beers here and there to friends' houses, or enter them in competitions. So, the idea of overcarbing an entire keg of beer to compensate for carbonation losses due to bottling a small number of bottles from said keg, does not really appeal to me.

I know to do some things that may help minimize issues, such as chilling the bottling device, the beer lines, the bottles themselves, etc, filling to the very top and bottling on foam, purging the bottle with CO2, etc.

Am I missing the "secret" that let's you bottle this way while maintaining the same carbonation level you get when serving from the keg?

 

[303Dan]

I decided to go with a Counter Pressure filler from MoreBeer so I could keep the keg serving pressure constant. Hopefully that will be the best of both worlds.

 

[m00ps]

I use a beer gun with my kegs and I havent had any issue with undercarbed bottles months later due to temporarily dropping the serving pressure. it takes a long time at the lower pressure for the beer to carb to that lower pressure

what about the counter pressure filler lets you keep it at serving pressure without foam?

 

[303Dan]

With a counter pressure filler, you pressurize the bottle itself, then use the difference in bottle pressure to serving pressure to control your flow into the bottle. So, you can in essence, create a very small pressure difference between the bottle and keg, forcing a slow pour and minimizing foam. Plus, you're pouring into a bottle pressurized with CO2. It seems like it's a little more work and more complicated to do by yourself (I guess I'll see once I try it myself), but to me it seems like it would result in more control and minimize loss in carbonation.

Maybe it's just my system, but as soon as I lower serving pressure on a keg already carbonated, I start seeing CO2 coming out of solution in the beer line. And if you're seeing bubbles in the beer line, by definition there is some carbonation loss going on, even if it's small.

Anyway, I just opted to go for the solution I feel like gives the most control over that. We'll see if I end up liking it.

Dan

 

[jmcquesten]

Here's my reply from a different thread about 5 minutes ago. This is the secret the I figured out that no one suggested when I asked around. Not sure how many people do it, but it works for me.

I think that's exactly what happened to me the first few times I used my beer gun. Beer was carbonated great pouring from the tap, but when I released the pressure on the keg and dropped to 2 psi, I still ended up with a lot of foam. I tried a bottle the next day and it was almost flat. I know the cap was sealed because I heard a slight hiss when opening.

I tried everything recommended, chilling bottles before filling, lowering pressure to almost nothing, over-carbonating to compensate for loss, cooling beer more to keep more gas in solution, etc. None of these tricks completely solved the problem. Then it occurred to me. At my serving pressures 14 psi - 18 psi, I need 15 - 20 feet of beer line to balance my kegging system and get proper carbonation without a ton of foam, so maybe that's the answer to my beer gun problems. I got a 20 ft piece of (3/16) beer tubing and tried the beer gun at serving pressure. It worked out really well with minimal foaming, and the bottles are just as carbonated as the beer in the keg was.

So, while some people have luck with the short piece of tubing and a really low dispensing pressure, I didn't. This goes back to properly balancing a kegging system and mikesoltys.com line length calculator.

 

[303Dan]

Here's my reply from a different thread about 5 minutes ago. This is the secret the I figured out that no one suggested when I asked around. Not sure how many people do it, but it works for me.

Interesting. For me, the CO2 coming out of solution in the beer line happens regardless of line length once I lower serving pressure. It happens with the beer just sitting stationary, not necessarily only when dispensing.

 

[jmcquesten]

Interesting. For me, the CO2 coming out of solution in the beer line happens regardless of line length once I lower serving pressure. It happens with the beer just sitting stationary, not necessarily only when dispensing.

Right. What I was saying is that if you use a really long beer line, you don't have to lower the serving pressure. If you don't lower the serving pressure, you get a lot less foam bubbling out of the beer. I think that when you lower the pressure in the keg, the CO2 starts escaping from the liquid trying to fill the headspace till it reaches an equilibrium. Every bottle you fill creates more headspace in the keg for the co2 to fill and the 2 psi isn't enough to keep the dissolved gas dissolved. If you keep the keg at serving pressure, the gas remains in the liquid and the co2 needed to fill the headspace comes from your tank, not the beer. Of course at serving pressure (12 - 18 psi in my case), you need a long line to slow the beer down enough for a proper pour (fill). With a short line, my beer was flowing too fast from the beer gun, which caused some of the gas to be released in the form of foam, resulting under-carbonated beer.

I still see some bubbles in the line, but not nearly like I did with the really low pressure. The bottled beer is a lot better now, so the bubbles in the line aren't a concern.

 

[Brettomomyces]

Something I picked up from Brewstrong that I'm going to try next time I use my counter pressure...Jamil recommends keeping the keg above the bottle and using the pressure differential to start a siphon from the keg into the bottle as opposed to having them both at the same height and using the CO2 to push the beer into the bottle.

 

[jmcquesten]

Something I picked up from Brewstrong that I'm going to try next time I use my counter pressure...Jamil recommends keeping the keg above the bottle and using the pressure differential to start a siphon from the keg into the bottle as opposed to having them both at the same height and using the CO2 to push the beer into the bottle.

I did try that. The biggest improvement I saw was adding the 20 ft beer line.

 

[303Dan]

Right. What I was saying is that if you use a really long beer line, you don't have to lower the serving pressure. If you don't lower the serving pressure, you get a lot less foam bubbling out of the beer. I think that when you lower the pressure in the keg, the CO2 starts escaping from the liquid trying to fill the headspace till it reaches an equilibrium. Every bottle you fill creates more headspace in the keg for the co2 to fill and the 2 psi isn't enough to keep the dissolved gas dissolved. If you keep the keg at serving pressure, the gas remains in the liquid and the co2 needed to fill the headspace comes from your tank, not the beer. Of course at serving pressure (12 - 18 psi in my case), you need a long line to slow the beer down enough for a proper pour (fill). With a short line, my beer was flowing too fast from the beer gun, which caused some of the gas to be released in the form of foam, resulting under-carbonated beer.

I still see some bubbles in the line, but not nearly like I did with the really low pressure. The bottled beer is a lot better now, so the bubbles in the line aren't a concern.

Ahh, ok, I see what you're saying. Yeah, I see how that could help.

Anyway, I ordered a counter pressure filler from MoreBeer, so we'll see how that goes.

 

[SeeMont]

This is a good discussion. I use the Beer Gun, I have a long line but I fill at about 5 to 6 PSI. My bottles are rinsed in ice cold Star San right before filling. I have had good luck filing this way.