PSI Level - Page 3 - Home Brew Forums

Register Now!
Home Brew Forums > Home Brewing Beer > Bottling/Kegging > PSI Level

Reply
 
Thread Tools
Old 10-24-2011, 11:52 PM   #21
Yooper
Ale's What Cures You!
HBT_ADMIN.png
 
Yooper's Avatar
Recipes 
 
Jun 2006
UP of Michigan, Winter Texan
Posts: 69,231
Liked 7732 Times on 5426 Posts


Quote:
Originally Posted by MKEbrew View Post
This is what I'm using.

Attachment 36690
Ok, a picnic (cobra) faucet. Do you open it fully when you dispense? What is the approximate keg temperature?

How long are those lines? They look short, because mine go around the keg about four times before looking that short but it's hard to tell in a photo.
__________________
Broken Leg Brewery
Giving beer a leg to stand on since 2006

 
Reply With Quote
Old 10-25-2011, 12:25 AM   #22
MKEbrew
Recipes 
 
Dec 2009
Milwaukee, Wisconsin
Posts: 101

I do open it fully, but it is under 5ft and has only been 9 days.
__________________
Mark

 
Reply With Quote
Old 10-25-2011, 12:31 AM   #23
MKEbrew
Recipes 
 
Dec 2009
Milwaukee, Wisconsin
Posts: 101

Sorry, and its 41 in the fridge.
__________________
Mark

 
Reply With Quote
Old 10-25-2011, 01:34 AM   #24
Brewerforlife
 
Brewerforlife's Avatar
Recipes 
 
Dec 2009
Marquette, MICHIGAN
Posts: 250
Liked 9 Times on 8 Posts


I think you need to add a little length to that line. You will need about 8-10 ft. of 3/16th vinyl. I would start with 10 ft. and work down from there, at 41F you should be all right between 10-15psi to get the right volumes of CO2 desired. Hope that help's!! CHeers!!!

 
Reply With Quote
Old 10-25-2011, 02:33 AM   #25
MKEbrew
Recipes 
 
Dec 2009
Milwaukee, Wisconsin
Posts: 101

Hmm, so lengthening the line is the only solution? I don't really want it longer or need it longer for any other reason... why does short tubing cause foam?
__________________
Mark

 
Reply With Quote
Old 10-25-2011, 07:33 PM   #26
Brewerforlife
 
Brewerforlife's Avatar
Recipes 
 
Dec 2009
Marquette, MICHIGAN
Posts: 250
Liked 9 Times on 8 Posts


Not enough resistance, in my opinion. Most books and other sources will say 3/16" vinyl will have between 2.2 to 3 psi/ foot of resistance, but in my experiences I have there to be less. Most people I know all use 8-10 ft at 40F and get a good pour. If you keep the 5 ft. that you have, you can simply hold & serve at a lower pressure, like 5-7 psi. But your beer will have low CO2 volumes and be under-carbonated. Even a beer that was properly carbonated to begin with, will eventually come to equillibrium with the lower head pressure and become under-carbed, and will also cause foaming issues as the excess CO2 is coming out of solution to equalize with lower head-pressure. If you ever look at your lines as they come out the keg, and you see bubbles coming up your line, thats the CO2 coming out of the beer!!! Hope that rambling helped some!! Cheers!! Chumly!!!

 
Reply With Quote
Old 10-25-2011, 07:47 PM   #27
shortyjacobs
Recipes 
 
Aug 2009
Twin Cities, MN
Posts: 2,509
Liked 34 Times on 34 Posts


Quote:
Originally Posted by MKEbrew View Post
Hmm, so lengthening the line is the only solution? I don't really want it longer or need it longer for any other reason... why does short tubing cause foam?
OK, science lesson:

Short tubing causes foam because the beer sees too big of a pressure drop at the end of the line.

Your keg is at, say, 12 PSI. The outlet of the faucet, by definition, is at 0 PSI, (really, these are called "PSIG" ,or PSIGauge. Gauge means, "set relative to atmospheric pressure". In fact, although your gauge reads 12 PSI, your keg is really at about 26.7 PSIA (PSIActual), and the outlet of the faucet is at 14.7 PSIA, or 1 atmosphere of pressure...but whatever).

If you all of a sudden jump from 12 PSI to 0 PSI, a bunch of foam will form, because the CO2 basically gets "shocked' out of solution.

Now, travelling through a tube "uses up" pressure. There is resistance to the flow of the liquid, friction with the tube walls, etc. The energy to overcome that resistance has to come from somewhere, and it comes from the pressure. The pressure of the liquid drops as it travels through the tube!

You want to "balance" the pressure drop with the pressure in the keg. Basically, you want enough tubing to "use up" that extra 12 PSI of pressure in the keg, so the beer exits the faucet at near 0 PSI. Because this drop from 12 to 0 PSI happens slowly, as the beer is travelling, the beer doesn't foam.

With only 5 feet of tube, you are probably only dropping the pressure down to 5 or 6 PSI. You need MORE tube to drop the pressure down more before it exits the faucet. Note that, because pressure is dropping, flow rate drops, so longer line makes your beer flow slower.

There are two answers to the problem: longer lines, or something else to drop the pressure. Some people use epoxy mixer sticks in the diptube of the keg, (search "cure short hose" on HBT to find the thread). The mixer sticks cause a lot of flow restriction, which "uses up" more pressure, and allows you to use shorter hoses. I personally prefer longer hoses, because the mixer sticks are finicky, and you have to make sure they are clean and sanitized each time you rack to a keg, which adds more vectors for infection. Both solutions, however are valid.

If you go with longer hoses, do NOT splice in more line. You need to ditch the 5 foot line altogether, and buy a 10 foot line. If you splice 5 more feet onto the 5 feet you have, the restriction caused by the barbed coupler you'll use will cause a drastic pressure drop, (called a venturi effect), and will create foam in the line, so you'll be no closer to the perfect pour then you were before.
__________________
Itchy Dog Brewery.

(As of 10-24-2011)
Primary - Steppe 112 PA, 2x Monday RyePA
Aging - None :-(
On tap - Big Dog, Apfelwein, Steppe 112 PA

My invisible AG sculpture, with no actual sculpture and a tiny footprint.
My Kegerator goes offroading!
My Coors Home Draft dispenser for boating/beering on the go.

 
Reply With Quote
Old 10-25-2011, 08:08 PM   #28
MKEbrew
Recipes 
 
Dec 2009
Milwaukee, Wisconsin
Posts: 101

Thanks for the thorough answers. Wish I would have just started with longer tubing because now I feel like I wasted money. Off to NB I guess.
__________________
Mark

 
Reply With Quote
Old 10-25-2011, 08:11 PM   #29
Yooper
Ale's What Cures You!
HBT_ADMIN.png
 
Yooper's Avatar
Recipes 
 
Jun 2006
UP of Michigan, Winter Texan
Posts: 69,231
Liked 7732 Times on 5426 Posts


Quote:
Originally Posted by MKEbrew View Post
Thanks for the thorough answers. Wish I would have just started with longer tubing because now I feel like I wasted money. Off to NB I guess.
Well, wait! There is always this option: http://www.homebrewtalk.com/f35/cure...oubles-100151/

For me, it was simply easier to lengthen my lines in the kegerator. But this could be an option for someone else!
__________________
Broken Leg Brewery
Giving beer a leg to stand on since 2006

 
Reply With Quote
Old 10-25-2011, 08:16 PM   #30
Bobby_M
Vendor and Brewer
HBT_SPONSOR.png
 
Bobby_M's Avatar
Recipes 
 
Aug 2006
Whitehouse Station, NJ
Posts: 23,205
Liked 1660 Times on 1073 Posts


Another thing to try is to just grab your picnic faucet and hold it up over your head and try pouring from there. The added height adds resistance. It would be enough to see if longer lines would do the trick. Seriously though, 10 feet of line shouldn't be more than 3 bucks.
__________________
Welcome to BrewHardware.com. I love you.
BIAB Large Mesh False Bottoms and SS HERMS COILS are IN!!
Chugger Pumps, Pump Kits, Camlocks, Sightglasses, Clear USA made Silicone Tubing, RIMS, Electric Install Parts, etc.

 
Reply With Quote


Reply
Thread Tools



Forum Jump