Copper or stainless

I am going to make me a new immersion chiller. A friend is going to get me the 3/8" tubing. He said he can get stainless or copper for about the same price. What do you all prefer, and why?

Copper; much better heat properties than SS

I don't have one but I would go with stainless. Copper is a contaminant in water. Granted you probably wouldn't get much copper in the wort from the short time the chiller is in there, and I think don't breweries often have copper fermentation vats, and much modern home water piping I suppose is copper too... Might get some nickel off the stainless though too I suppose.

I use SS with no ill effects....copper does conduct better though.

I'd go copper. I've HEARD that SS is a real pain to bend without kinking. Also, I'm no chemist, but I've read that copper ions help when they're in the boil.

Here's the article in BYO about metals in brewing. Never put copper in the fermentation.
http://***********/stories/projects...d-it-yourself/1149-metallurgy-for-homebrewers

and here's the quote about copper in the boil
Copper is a double-edged sword in brewing. It is beneficial before fermentation, but detrimental afterwards. Copper ions react with the hydrogen sulfide produced during fermentation and reduce it to insoluble copper sulfide, which is left behind with the trub and yeast cake. Switching to all stainless steel brewing equipment can lead to noticeable quantities of hydrogen sulfide and sulfur off-flavors and aromas in the beer. The use of copper wort chillers will provide all the copper necessary, as will including a short piece (1 inch) of copper tubing in the boil.

Or just go all out, get 1/2" and leave the rest up to me.
https://www.homebrewtalk.com/f41/89...iller-free-shipping-limited-time-only-359923/

Interesting info about the copper and H2S. Hm ... so should we drop a couple pre 1982 pennies into primary?

I've heard that copper is natually somewhat anti-bacterial too... Be careful going to 1/2" if your only doing a 5 gallon batch. I have heard about some problems with that in regards to too much surface area being exposed to the water and it not being as effective... I know I am not emplaining that well but there are some issues apparently...

Hm yes might have something to do with heat exchanger efficiency, like there is a limit based on flow rate, temperature differential, etc. Unless maybe you want to go to finned tube, that seems like it would be a pain to clean. Maybe it also leaves the water in the middle of the flow stream cold while the water on the outside is warm, there is some kind of tube that has like these 'swirly' things in it to mix the liquid as it flows and I forget the name completely now, I know I have seen it in petrochemical applications.