Metallic/Tannic Taste - StarSan & Plate Chiller?

Northern Brewer General
1

I’ve been getting a slight metallic/tannic taste in all of my beers.

My process has been …

Sanitizing my 30 plate Duda Diesel plate chiller with StarSan, I typically let the solution sit in the chiller for 30 to 45 minutes, drain, then refil with the same solution. I noticed the last time that the StarSan exiting the chiller was cloudy and not clear as it went in. Using distilled water, my StarSan is crystal clear. Only does it change when it runs through the plate chiller.

I met with a commercial brewer today who tasted my beers and confirmed a slight metallic/tannic taste. Nothing over the top, but present.

When discussing my cleaning, he felt that my sanitizing process may be the root of the problem. That by leaving the StarSan in the plate chiller it was altering the pacification and that by immediately using the chiller, without allowing the pacification to reform, may be allowing the hot wort passing through it to pickup some of the metallic taste.

It was suggested that the plate chiller did not have time to repacificy.

Does this make any sense?

Will a solution of StarSan somehow strip the protective pacification from the inside of the plate chiller? If so, how do I repacify?

2

StarSan has a 30 second contact time. You’re overdoing it by a lot. I’m no metallurgist, but I’d bet that acid + metal is at least contributing to the flavor you’re experiencing.

3

I am going to flush it with boiling water (a few times) then bake it in the oven to dry it out.

On brew day, I’ll just run boiling water through it instead of StarSan.

4

A metallic taste is more often associated with oxidation issues. People put their ICs in their boiling wort all the time, that is more contact with copper than you are seeing with the plate chiller.