I just wanted to give every new kegging brewer out there a heads up on how important clean lines are. I have been kegging since March, and I have had about 6 different batches on tap so far. I have been very lazy about cleaning because I didn't have a good method to do so yet, and would hook up keg with cleaner/water once every other month or so. I didn't taste any "bad" flavors but i thought my brews were missing something. Also my kegerator is outside and with a tower, so I would have to pour a few oz off each new day I went to get a pint, to get the warm, flat and funky beer out of the lines.
Well I just did the pump sprayer DIY cleaner setup seen on this forum and about half a keg into my latest ordinary bitter, I am really tasting it for the first time!! I am shocked how huge the difference is, it is a great beer, and was just a mediocre beer.
so if you are new to kegging and unaware... CLEAN YOUR LINES!!! You will be happy you did.