I just finished my first batch of beer and unfortunately when it was finally finished aging the beer came out a little metallic.
What do you think could have caused this?
The metallic taste is typically derived from iron somewhere in your brew process, so you’ll want to look for a source.
The other thing that it could be, is just how the yeast interacted with the malt. It can get a twang that becomes metallic to you palate. I just had this experience with a dry yeast in a red ale. It mellowed after a couple of weeks though…
What type of water did you use? Is it city water or well water? Wells can have very high iron and sulfur content, making them unsuitable for brewing so you’ll want to test your water as a starting point.
When you make your wort, the type of pot you use can also add to this flavor. Ceramic on steel pots, with chips in the ceramic expose the wort to the metal (often rusted) beneath. The same is true with metal spoons, valves, fittings or any other potential source of iron.
Stainless steel is that way because of an oxide layer that doesn’t allow rust to begin. If the pot has been scrubbed hard, the protective oxide can be removed, exposing the iron in the steel to the wort. Once this happens, then the pot needs an acid bath to restore the oxide.