In my last 3 brews I am picking up a slight off flavor. Some of the neighbors do and don’t taste it. To me it’s like a “dirt” from the potato patch- I wouldn’t call it metallic, but my one buddy got that. It’s enough that I won’t serve or drink it. First I dumped all my yeast starters, scrubbed everything and started over. No luck. So working through the possibilities I narrowed it down. I brew and ferment in stainless. Could too much StarSan left in the fermentor leach out the metal taste- if so can I fix this? I ferment in a ½ keg- it’s hard to scrub it out. Or is it my copper manifolds in my mash tun and boil kettle that are doing the same thing? Or a crazy infection somewhere through the process? This one’s got me nuts and I have already dumped 20 gallons of beer. I never had this problem on my old system of a 60qt cooler mash tun and glass carboys. Thanks everyone.

Is there a reason that you are fermenting in a hard to clean vessel? How long since you replaced tubing and the like? Just trying to think of some possibilities.

any changes in your water supply. How old is your carbon filter?

You need to be careful about letting starsan come into contact with copper. Could this be the problem? After exposing copper to acid, it needs to dry completely and you need to allow enough time for the oxide layer to re-form.

Maybe its overcarbonation ? Also, are You using any dodgy plastic / rubber hoses for your brewing liquor ?

i also ferment in kegs and don't find them hard to clean. best thing is they are easy to sanitize. during my mash, i boil RO/DI water in my fermenter keg for about 30 minutes to heat sanitize with steam. how are you sanitizing yours?

+1 Beltbuckle. Ive been doing the same without issues. Id suspect water filter as well. What if you went to bottled water ? Same results?

The one time I got a metallic taste was from how I was racking the beer from fermenter to keg. I had a brass fitting I was using to reduce tubing size from 1/2" to 1/4". Before racking everything was sprayed with startsan, and just having one brass fitting in there with starsan on it made the finished beer pick up a little metallic taste that about 50% of judges could pick up. I knew brass and copper goes funky after sitting in starsan for a while, but just a brief exposure is enough. switched to a stainless fitting and now have a policy of no copper or brass anything past the boil kettle/wort chiller.