Metalic Taste

[BrewinMAINEiac]

I just tasted a friends cider. He has been doing it for years. He uses oak barrels to ferment a non-sparkling cider. I am getting a metallic end note on the taste. Good flavor but that metallic taste just after you swallow is a buzz killa. Bottles and caps were clean and in good shape (no rust). It seems to fade as you get to the end of the bottle but its probably my pallet getting use to it. Any thoughts as to where it comes from?? thanks

 

[gratus fermentatio]

You might find this useful:
http://winemaking.jackkeller.net/problems.asp
Scroll down to "Metallic Flavor."
Same is true for cider. Regards, GF.