Wort being boiled in unprocessed Metals , mainly iron , but also aluminium , and steel ( excluding stainless ) is usually the source of metallic flavors .
Metallic flavors can also be extracted from metal brewing equipment , bottle caps and/or kegs .
Using Water that has high levels of iron will impart iron flavors .
Avoid using iron for anything that will be coming in contact with Beer/Wort .
If using a ceramic coated steel Pot , always check for cracks or scratches before using .
Aluminium Pots will generally only cause metallic flavors when using Alkaline Water with a pH over 9 .
Avoid using unfiltered well Water which has high levels of iron .
Besides , I would dissolve a little of the Honey in a glass of Water ( the Water you used for brewing ) and taste it to see
if there is any detectable iron flavor .
If you used Honey as an Adjunct , did you add it near the end of the boiling ?
I've heard also that some Chemicals are sometimes added to Honey to pasteurize it . Perhaps These Chemicals have an effect on tasting .