I've been homebrewing for about a year, and done about 20 5gal batches so far, and bottling.
Never had a bad batch bottling - beer was so good it made me want to start a brewery.
Then just a few months ago, I upgraded to a 4x Keg system which I installed taps into a fridge.
A single C02 cylinder, single regulator is stored outside the fridge, with a low pressure air line going into the side of the fridge into a 4x air block, from the air block to each of the kegs.
Here is where my problems began...
After getting the kegs, I followed the standard sanitation practices i did with bottling, using a PBW solution in the keg, pumped it through the lines, then sanitized with iodophor, and pumped it through the lines.
Setup information: Keg pressure is 10psi, Taps are at level with top of the Keg, Beer lines are approximately 4ft.
Keg 1: Kegged a cider, was great.
Keg 2: Kegged a pale: went all kinds of wrong.
History: Tasting out of primary, tasted good, tasting out of secondary tasted fantastic. Kegged and naturally carbonated using 1/3 cup dextrose. Left 3 weeks, then refrigerated, and hooked up CO2 @ 10psi.
First Day: taste was flat (like it didn't carbonate), but it tasted fine (not sweet)
Second Day: tasted kind of sweet, excessively foamy (all foam, no beer)
As time progressed, it got sweeter and sweeter (I left the C02 hooked up, just in hopes it would get better)
Keg 3: Kegged a Ginger Ale, Force carbonated, tastes fine, no excessive foam (no excess sweetness is noticed, however it is HEAVILY ginger-fied, so this might be covering up any sweet taints)
Keg 4: IPA, naturally carbonated using 1/3cup dextrose, pressurized keg lightly to ensure there was a seal on the top this time (as opposed to Keg #2)
Let sit for 3 weeks. measured pressure in keg before refrigerating (pressure from C02 pressure + carbonating pressure)
After refrigerating, hooked up to CO2 line, tastes great, slight sweetness, but masked by intense hop aroma and flavor... this beer is good, but could be better (that hint of sweetness bugs me)
Keg 1 of cider, ran out.
Cleansed and Sanitized Keg 1 and lines and tap.
Kegged a light ale, this time force carbonated (as all of my natural carbonations have failed either terribly, or were so so).
I charged it with 10psi, then let it sit in the fridge overnight to get down to about 34 degrees. Then I used a second C02 bottle and pressurized the keg to 40psi, and shook the keg till no more C02 would come out of the cylinder (this was done audibly from the regulator). I let it sit overnight, then did the same thing the following day, then I let the beer sit overnight again.
The 3rd day, I purged the air, and connected it to my 10PSI line, and pulled first draft.
It was overly carbonated (it hadnt been at 10PSI for long at all), so I figured it needed time to equalize. But it tasted great - crisp and dry (no sweetness)
I let the keg sit, then today is Day 2, I pulled a sample, and it still foamed up (all foam, no liquid) - obviously it was flat when it settled, however - it has started to develop "the sweetness"
Its driving me crazy.
So this brings me to my questions:
1) Could a "sweet" beer in another keg (I'm thinking Keg #2) taint a beer in another keg (thinking Keg #4 and the second use of Keg#1 above)
2) Has anyone ever experienced this before? I have been searching and cannot find any hints so far
3) When kegging and trying to naturally carbonate, has anyone had a problem keeping a seal and the beer failing to carbonate? (referencing Keg #2 and Keg#4 above)
Thanks for all your help!