I'm a fairly new brewer and I am making a transition into all-grain brewing. I've made 2 batches so far which have turned out great however, I've noticed a metal taste in the beer that I cannot pinpoint where it could be coming from. I'm using star-San and letting it dry. Stainless boiling pot and a homemade mass tun with a stainless filter. Where could I be going wrong? Thanks.