The foam shows up about half-way along the line...the line closest to the keg looks to be filled with beer.
Keeping the tap open - well, I guess I'd say no since I filled a few pint glasses and the "Beer" never reaches the glas - just foam. Regarding the temp - I was wondering about that as well - but since the whole cpoil of line is in my freezer it should all be cold.
I'm wondering - if the pressure in the line gets too low as the beer proceeds along - maybe its hits a point where the foam is encouraged due to low external pressure - then its the CO2 coming form the beer that pushes it along then on.
I can always cut back the line to 20 ft and see whether the beer hits the end.
I know its tough to serve beer at this carbonation - but in the commercial dubbels I've had the higher the carbonation the better the beer tastes to me, and this level is the recommended for the style.
Thanks!!!
Have you watched what's happening in the line as you pour a beer, or are you just guessing? If you've actually watched it do what you described, it sounds to me like the line is warmer than the beer in the keg. Is the line at the top of your freezer, where it could be a few degrees warmer than the bottom of the freezer?
Did you use the set and forget carb method, or one of the burst carb methods? If you didn't use the set and forget, it's possible that the carb level is higher than the serving pressure, which could explain things.
There's no such thing as foam caused by lines being too long. The ONLY negative effect of excessively long lines is a slow pour. No matter how long the line is, the beer is always transitioning from keg pressure to atmospheric pressure during the pour, so lower pressure inside the lines isn't going to create more foaming than a shorter line with higher pressure. In fact, the slower this transition occurs, the less CO2 will be knocked out of solution.
How slow is the pour exactly? With your figures it should be filling a 16 oz glass in ~14 seconds, which is slow, but not what I would call a trickle. If your pour is significantly slower than that, you may have an obstruction or other issue that's causing the foam. And for 3.5 vol I don't think you'd want the pint fill time much faster than 14 seconds if you expect to keep much of the carbonation in the glass.