Help with off flavor

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.

Can you go back to your old system, brew a batch and see?

Starsan wouldn’t cause an off flavor unless it was A LOT of it that got in there.

[quote=“Jonh Palmer”]Metallic
Metallic flavors are usually caused by unprotected metals dissolving into the wort but can also be caused by the hydrolysis of lipids in poorly stored malts. Iron and aluminum can cause metallic flavors leaching into the wort during the boil. The small amount could be considered to be nutritional if it weren’t for the bad taste. Nicks and cracks ceramic coated steel pots are a common cause as are high iron levels in well water. Stainless steel pots will not contribute any metallic flavors. Aluminum pots usually won’t cause metallic flavors unless the brewing water is alkaline with a pH level greater than 9. Shiny new aluminum pots will sometimes turn black when boiling water due to chlorine and carbonates in the water.

The protective (grayish) oxides of aluminum can be enhanced by heating the clean pot in a dry oven at 250°F for about 6 hours.

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