Keg Coupler 5/16 and 3/16 beer hose causing foam?

[Kramerah]

I am new to the kegerator world, however I built my own standalone out of an old refrigerator. The fridge is 5-6' away from the wall where my tap is. I ran 2 insulated PVC from the fridge to the wall. I also installed a 20 CFM blower with tubing all the way to the shank. Beer is mich ultra. 1st and 2nd pour are both 37 degrees, so I know that I am not getting warm in the PVC, however I am getting about 1/2 a glass of foam. It appears that i have a small amount of turbulence as soon as I open that handle that creates a small amount of foam, which turns into more foam as I pour. I am set on 12PSI right now. I have turned the PSI up to 14 and 16, however when I turn up the PSI the foam gets progressively worse with the higher PSI. If I turn the PSI down to 10 I get a great pour, but am concerned with beer going flat. I do have 3/16" food grade line that is about 9' long. My question is my keg coupler has a 5/16" barb fitting on it. I boiled some water and pressed the 3/16" line onto the barb fitting. It fits great, however I am wondering could going from 5/16 at the barb to 3/16 hose create the small amount of foam I am seeing at the beginning? Any help would greatly be appreciated.

[Dan Berumen]

I would suggest that you redo your line. Do about 51/2 ft of 3/16th line and do the remainder that you need 5/16. Start your pressure at around 12 and play with it one lb at time. Also, take a temperature of the first pour, after it hasn't been used for a few hours. That will tell you if your beer is getting warm in the chase.

[djc]

There is nothing wrong with 9' of 3/16", and adding 5/16" will only aggravate things. If you had a transition problem from the coupler, you would see the spurt of foam after a few ounces, not immediately at the faucet. What type of faucet are you using, forward or rear closing, and are you opening it all the way right away? Your numbers for beer temp are suspicious to me - it is nearly impossible to think that the temp is exactly the same from the first pour to the second pour 6' down the line, regardless if it is air cooled or not. What technique are you using for taking the temp, and are you using a calibrated thermometer? What does the beer line look like when it is at rest - solid beer, or bubbles at the high spots (like behind the faucet). Bubbles indicate you are not balanced. Balance is a mathematical correlation between the V/V of the beer and the applied pressure using a Zahm Nagle chart. Pressure isn't something you just bump up and down at will, at 37 degrees using a V/V of 2.6 the beer is looking for 12-13 psi for proper balance.

[Kramerah]

Its a rear sealing faucet and I am opening all the way at the beginning of the pour. I am using a fieldpiece wire thermocouple thermometer that i did calibrate in ice water. Behind the facuet is sealed with the PVC pipe, but I will check tonight what it looks like as far as bubbles. There are no bubbles at the coupler, but I am assuming this wouldn't mean much since they would migrate up to the faucet. I will take additional temps tonight on first pour vs 2nd and report back. I did notice last night that where the PVC is cut into the side of the fridge it is slightly lower than the coupler height. Could this cause an issue at all? Thanks for the help

[djc]

When you take the temp, are you starting with a room temp glass, filling it, and then immediately pouring it off and refilling it? You also need to be taking the temp of the beer and not the foam, without touching the side of the glass. When you start the pour on the second glass, is there still a burst of foam or is it a solid stream of beer? The reason you take the temp on the second glass is because that is the actual beer temp and it is the temp you balance to since it represents the beer coming off the bottom of the keg. The bubbles will migrate to the highest point in the line, not necessarily towards the faucet. The height difference between the coupler and faucet is irrelevant.

[Dan Berumen]

Guru says a lot of important sounding things. But trust me, your beer will not pour properly if you have 9' of restriction and your pressure is set at 12lbs. Follow what i said in my first message. It's easy to do. Try it and see what happens.
I have been a draft service tech/ supervisor for 26 years and work for one of the 10 biggest distributors in the US. trust me, beer is not that complicated.

[Dan Berumen]

if you can get your hands on some 5/16ths inside diameter polyethylene line, use that after the 51/2 ft. of 3/16th restriction line. Poly line will offer very little drag. your beer will repack on the restriction line.

[Kramerah]

Ok I retook temps tonight. First pour way 38.1 and second pour immediately after was 36.9. First pour had about half a glass of foam while second had about 4” or so. Do I buy I 3/16-5/16 connector?

[djc]

Dan never came back to finish dispensing wisdom? Shocking. In any event, most installers have a very different set of rules they live by. They are looking for 8 second pints, and don't care a huge amount about the bar keep pouring off a little foam into the drip tray. If they are getting 90% yield they are happy. Home draft is a little different - no plumbed drip trays, waste is all waste without a customer to foot the bill. I've had 10' lines for 8 years. The longer line slows the flow of properly balanced beer. It doesn't get much simpler than a straight run of the same diameter line, although Dan suggests splicing lines is easier. Your temp in the chase is pretty good, a first beer without perfect temp matching will always have a bit more foam. I'd leave the 9' line, and agree with Dan on bumping it up a pound or two. The adjustments take time to have an effect - it needs to sit for 24 hours or so before you do anything else. Always adjust 1 thing at a time.