How much pressure for a CPF?

[BigNastyBrew]

Decided on the counter pressure filler. I just like the design better. I watched the B3 video a couple times and I think I have a good idea on how to fill the bottles.

My questions are:

1. do I relieve the pressure from the keg first and then use the CPF?
2. How much pressure do I set my regulator for while using the CPF?

[bcmaui]

Should I ever get one of these, I have been instructed to make a video of my first attempt at using it.

[BigNastyBrew]

Should I ever get one of these, I have been instructed to make a video of my first attempt at using it.

My LHBS owner says I should do it outside the first time.

[meisterofpuppets]

First time I used mine, I tried to turn the beer valve off. I turned the valve to far to CO2 purge. Beer flew all over the place. 'Twas nasty.

[BigNastyBrew]

Funny. I'm sure I'll have a beer bath too.

But what PSI do you run on the CPF?

[ajdelange]

I'm not familiar with the B^3 filler but on the assumption that it works like most, here goes. You will want your beer (in the keg) carbonated to a slightly higher level than what you want to serve at because you will lose a little gas in the filling process. "Capping on foam" obviously costs the beer some CO2. When you get the hang of things you won't lose much so perhaps 5% over should do. For example if you wanted 2 volumes, set pressure for 2.1 at whatever temperature you are carbonating at and wait (a couple of weeks) for the new equilbrium to be reached. A better plan, of course, is to set for 2.1 when you keg the beer, bottle when at equilibrium and then back the pressre off for serving if you find the extra 5% too gassy (not likely).

The pressure you set during filling depends on how long you plan to keep the beer in bottles. Suppose that the beer is in the keg at 14.7 psig i.e. 1 atm gauge or 2 atm absolute. Now suppose you set your filler for 29.4 psig i.e. 2 atm gauge or 3 atm absolute. When you pressurize the bottle with CO2 to 3 atmospheres and then purge down to 1 you are letting out 2/3 of the gas i.e. 2/3 of the CO2 you just put in and 2/3 of the air (assuming the air and CO2 mix uniformly) so the first purge at 29.4 psig takes the air down to 1/3 of a bottleful. A second purge with the same pressure reduces the air to 1/3 of 1/3 or 1/9 of a bottlefull, a third to 1/3 of 1/9 or 1/27th of a bottlefull and so on. If you fill bottle 95% full that leaves 1/20th of 1/27th of a bottleful of air which, for a 355 mL bottle (12 Oz) is about 0.7 mL air. Numbers like this are what you want for prevention of oxidation during long term storage. From this point of view you want the highest pressure possible on the filler for purging air but there are, of course, practical limits not the least of which is the danger that an over pressurized bottle may burst causing injury (my filler clamps the bottle onto a stand behind a piece of plexiglass). I'd say 30 psig is about as high as you can reasonably go and I'm not sure what the implications of a pressure that high might be with a hand held filler.

Now if you cap on foam (rap the side of the bottle after filling with a rubber or plastic mallet or the handle of a screwdriver to the point where foam begins to rise in the neck and pop on the cap when the foam reaches the lip of the bottle) you shouldn't need to do these multiple purges (which are costing you CO2) nor would you need to use such high pressure. This is how the $400,000 bottling machines in a brewery do it (except that they shoot a stream of hot, sterile water into the neck rather than employing people with hammers). I don't have any way to do a calculation of cap on foam so I use three purges at 30 psig (being a sort of anal type) and cap on foam in the hopes that I am keeping airs under control. I don't bottle much but what I do seems to have been spared the ravages of oxidation using this method.

I'd look to the manufacturer of the particular device you are using for guidance.

[SKymax]

I'm not exactly sure what design CPF you're using, but I've got one that I use all the time. Here's what I do:

I pressurize the bottle at about the same pressure as what's in the keg (or slightly higher). If it's slightly higher, when you turn the beer flow on, it will just push the beer back in the line slightly. Then I release some of the CO2 pressure in the bottle, and the beer will flow into the bottle until the pressures equalize again. Then I release a little more bottle pressure, it equalizes, etc... Just keep doing that until the beer is close to the top of the bottle. Then turn off the beer flow and release the rest of the bottle pressure.

It'll take a little bit of practice to figure out when to shut the beer flow off. You don't want the bottle too full, otherwise it'll foam up and make a mess.

Anyway, I guess the process is a little hard to explain in text. I hope this helps in any case!

[Mylo]

WOW! AJ's posts really take it to another level. That brotha needs to guest star on Brew Strong!

I use my CPF at the same pressure as the keg storage pressure. As long as your stopper makes a good seal to the bottle, then you should not have any issues with foaming. Since my kegs are stored down below my bottling surface, I found that if I let my bottle equalize to keg pressure after purging, then when I open the beer valve, it drops a foot or so back down the beer line. Then, even if I open the pressure relief valve slowly - the beer shoots back up the beer line very quickly and gives me too much foam in the bottle. So..... I never completely close the PRV after purging. I leave it open just a cunt hair. Then I quickly shut off the gas and open the beer valve - at which point the bottle starts filling at a nice slow rate. I stop the flow with the PRV when the foam hits the stopper, then close the beer valve, then open the PRV again. Finally I lift the CPF out of the bottle, and slightly open the beer valve to dribble some foamy drops of beer until I can cap on foam.


Good luck, Nasty.


Mylo