Weeeeeellllllllllllllllll...................that didn't fix it.
I just brewed my spring water batch (no additions, no lactic acid) and I got pretty much the exact same beer.
So here is a sort of table or matrix of Bad Beers over the past few months:
Name - Water used - Flavor - Sparge Method
Three diff. IPAs - Tap water - Awesome...did Tricerahops, pliny, winter ale - Fly
Tricerahops - Tap water - Cardboard\astringency turning to medicine - Fly
SN Celebration - RO +CaCL\Gyp - Cardboard\Astringency but no medicine - Batch
IPA - Same but also Lactic Acid - Cardboard\Astringency but no medicine - Batch
SN Celebration - Spring Water - Cardboard\Astringency but no medicine - Batch
I think the bad medicine flavor in the first batch was from the same problem I'm having now compounded with chloramine suddenly being in my water. The water dep. says they switch wells sometimes. That is now fixed I think, hence no medicine but the cardboard etc remains. That could be a bad hypothesis
Also I've been sanitizing more and more thoroughly each time...soaking for HOURS in PBW then sanstar, replaced all plastic parts, etc. These beers are so astringent they make your tongue go numb in the back for a long time. Tongue is numb right now as a matter of fact.
I gave some to a friend (thought I might be crazy) and she said they had a finish that reminded her of newspaper\ink\cardboard. My Mash temp never gets very high and even the lactic acid OVERDOSE batch had it (2 tsp total) so I can't imagine I'm leaching tannins but maybe I am - post-sparge wort is mildly astringent. I never get above 168 during sparge. Could it be that I'm not immediately boiling my Wort from my first runnings and the reaction is continuing? Residue in mash tun? Reaction to wort chiller? It's only like 10 batches old. Maybe wort chiller + star san? As you can see, I'm banging my head against the wall for answers.
For those that weren't following this thread earlier, I had 3 awesome AG batches and now ALL new ones are bad. I refuse to think its an infection...this last batch it was all new plastic, a 2 hour PBW soak in a carboy and a 2 hour Sanstar soak. Flavor is there with or without PBW.
Finally this flavor is in very aged beer that has been primary\secondary\cold crash\kegged\conditioned. It maybe gets a bit milder but doesn't go away. My first three AG batches were awesome after 7 days in the primary! I even redid one of my first good recipes and the new ones were AWFUL. Sigh.