Problem bottling / canning from unitank

[Henesy]

I currently bottle or can after brewing directly out of my ssbrewtech unitank using a blichman beergun. I used a beer line calculator to make sure I am using the right length and diameter of hose between the tank and gun so I don't get foaming, and I am using my glycol chiller to chill the beer down close to freezing before bottling.

When I first start the process, everything is fine and I get good cold, carbonated beer flowing into my bottles and cans with little to no foaming. However, and the process progresses, I get more and more foam in the line until, when I'm about 3/4 of the way through the process, my can's are filling to 1/2 to 1/3 foam. I assume that I am somehow messing up the PV=T equation here, and there is some sort of, e.g. pressure drop in the unitank which is causing the beer to foam as the volume decreases. The confusing part to me is that I am monitoring the pressure gauge on the unitank through the whole process, and it's never dropping, so I can only assume the problem lies elsewhere.

Has anyone had similar issues, and if so, how did you fix it?

 

[Golddiggie]

Not had that issue, but I'm using Spike CF10 conical fermenters (currently) and a Tapcooler filling setup. I canned a batch last Sunday and I have very little foaming from start to finish (about 5-1/2 gallons went into cans, after filling a 2-1/2 gallon keg). I even turned off the glycol chiller at the start of the process since I didn't think it was needed for the rest of that time. I also go for about 38F to carbonate, and package.

I did use my beer gun before getting my first Tapcooler setup, and had foaming issues too. Not as easy to get a full fill as with the Tapcooler, IME.

With a counter pressure filler, especially one with a ball valve, it's easier to control the flow rate. It's also easy to be sure you're filling from the very bottom of the can. Since the filling wand is telescopic, and you set it up so that it retracts just enough (when you put the first can onto the setup) to be filling from the very bottom.

I'd try reducing the rate the can fills, with the beer gun. Opening it a tiny amount at the start could help. Since you get most of the foaming effect when the initial beer flows into the can. Once the end is submerged, you should get less foam, depending on the fill rate. With the low temperatures you're at, you shouldn't need much pressure to get the beer carbonated.

BTW, how long is the line from the tank to the beer gun? ID of the line?

 

[Henesy]

BTW, how long is the line from the tank to the beer gun? ID of the line?

It's about 15' of 1/4" i.d. tubing.

I found this other thread after I posted and suspect this might help explain my problem. I am thinking my problem might be the regulator pressure into the Unitank. I'm not sure I have been setting it at/above the pressure the unitank is starting at. The unitank pressure is staying where it started, but now I suspect that is due to CO2 coming out of solution to make up for the fact the regulator is set lower than the tank pressure.

I'll make sure I do is the way Advanced describes in his post, and report back on the results.

 

[Bobby_M]

Switch to about 10 feet of the 4mm ID EVAbarrier tubing for one thing. That stuff will push right over the beer gun tubing. The way you describe your problem it could be two things. First, like you said your input pressure may be too low. Once you get that up higher, the 4mm EVA will keep your fill more under control.
The second thing is that your beer level is dropping and less and less of the coil is touching the beer. It could be warming up a bit.

 

[Plop]

It's about 15' of 1/4" i.d. tubing.

I found this other thread after I posted and suspect this might help explain my problem. I am thinking my problem might be the regulator pressure into the Unitank. I'm not sure I have been setting it at/above the pressure the unitank is starting at. The unitank pressure is staying where it started, but now I suspect that is due to CO2 coming out of solution to make up for the fact the regulator is set lower than the tank pressure.

I'll make sure I do is the way Advanced describes in his post, and report back on the results.

How do you keep your fermenter under pressure during the transfer?
How do you measure the pressure? With the pressure gauge that comes with the unitank?