Hey guys, I'm pretty new to kegging and my last 4 brews are having the same little taste that I dislike. I had a bar before and before I sell it I took the spare 5 pounds co2 tank with me it was a 1994 tank. I connected 3 beer and they was fine. When it was empty I fill it where my lhbs store refer me. Because it was a 1994 tank they needed to test the tank before fill it. Since, I have that taste in my beer. I carbonate on my beer by putting 10 psi and leave it for 3 weeks and the last one was obvious I took a sample each week and it was tasting really good. Today I took a sample of 4 oz maybe and it was under carbonate but was really good so I decided to take a full glass and finally the pour begin to be foamy but just enough and by tasting the carbonation was good ( maybe the first sample was in the beer line). BUT the taste was not the same. My DIPA with 500g of hop in a 40 L batch that was smelling really good now looses that taste and is tasting the same thing as my other 3 last brews. Could it be fill with a bad co2?
Sorry for the long scenario but just wanted to tell everything.
Thanks in advance for the answer.