Anyone ever use a stainless steel immersion chiller? I’ve seen a few advertized, but never seen any comments on them.
My newbie thoughts are, they probably don’t cool the wort as fast as copper, since SS has poorer heat conductivity. The only advantage might be less tarnish/easier to keep “shiny”. But haven’t read about major concerns about that from the more experienced brewers on here.
I’m not really in the market for one right now. I just thought I’d throw it out for discussion.
I would agree that it wouldn’t be as efficient at transferring heat as copper, and that would be the biggest concern. You want to chill wort as rapidly as possible to your pitching temperature. Copper is the best metal to do this with.
I use a SS version, but I also double-up on cooling and run wort through a counterflow chiller too. I haven’t had problems and can get the wort down to pitching temp in no time.
While the conductivity of the SS is not as good as copper, the limiting factors are the wort transfer coefficient and the water transferr coefficient, which are really low. The SS is probably about 90% as effective. The coefficient of SS is around 16, copper 400, and water/wort around 0.58, units of (Watt/meter-degree C).
And if you ever want to go the HERMS route, the SS would be preferable.
If the cooling capacity is not much different, and cost difference is negligable, then why aren’t they more popular? My guess would be, copper is much easier to work with for the DIYer? Plus the “that’s what we’ve always used” reasoning?
Why is that, Tom?
The main reason I use copper is for the performance factor but the other reason being as you have mentioned is “the do it yourself factor”. By that I mean I was able to purchase 50 ft of soft copper and make my own chiller using a corny keg and a few fittings. It’s alot easier to bend and wrap soft copper than SS. So there’s two good reasons to go with copper over SS. 
Cheers,
Ron Price
Copper is easy to work, available, and was not that expensive for 50 ft of 1/2 inch at the big box.
Don’t know where I would get a roll of SS. Maybe McMaster-Carr. I would not try and wrap that around a corny keg to form it.
SS is more durable and can stand up to harsher chimicals if you wanted to do agressive cleaning. That being said, my copper chiller will last longer than I will.
My concern is immersion chillers can get a bit of rough treatment from time to time. If the stainless gets scratched- say from sitting on concrete then that’ll open the way for rust, which might not be apparent at first.
I’ll second that. I can’t figure out for the life of me why it would make a better HERMS.
One of the nice things about copper in the BK is that it adds trace elements of zinc, which is a very good yeast nutrient.
Tubercle’s 0.02
“Shiny” factor is on the bottom of my list.
Performance and bang for the buck is on top.
Could internal (therefore not easily detectable) verdigris be a concern?
I consider stainless to be stronger and more corrosion-resistant than copper.
My copper coils all are bent out of shape and covered with oxidation.
For homemade stuff copper is easier for me to do. I can bend it and solder it.
But overall I consider stainless a superior material.
Doesn’t the beer stay on the exterior of the coil? Unless you are returning the coolant to something you are consuming I wouldn’t see this as a problem.
Yeah, that’s the case when using an immersion chiller, but I was referring to the statements above about HERMS coils.
It doesn’t matter at our level, they both do well. I have one of each, the biggest difference is the rate of the water flowing through it. I used to recirc with a pump - then I brewed outside last session with a garden hose connected. Wow was that fast! :o