A little chemistry on a new wort chiller

My first post--be gentle.
A friend of mine donated about 30' of 3/8" copper tubing he found in the shed of a house he bought. It looked as though it had never been used and was in good shape. I took it home, introduced it to steel wool, wound it around a paint can and--voila--wort chiller. However ... I did get a few spots of silver-bearing solder on it while I was piddling, but torched the solder and removed it with steel wool and rescrubbed the beejeezus out of it (you can still see silver marks where the solder was, though). Took the coil inside and boiled it for 40 minutes. When I took the coil out of the pot I noticed a white residue along the pot's water line and all around the copper coil as well.

Now, I don't know if this is an ionic salt resulting from the copper/tin/silver of the solder and tubing combining with minerals in the water or what; could be, I'm not positive. I will reboil a few more times to see if it will subsist or hopefully disappear but in the meantime I was wondering if anyone had any ideas? Does this happen to anyone else and their chiller on a regular basis?

-me

i don't know what that might be, but as long as you used the same sort of solder that is used on household copper water pipes, it'll be fine. lead solder would be bad.

sounds like you've cleaned all visible dirt from your copper coils. now soak your chiller in distilled white vinegar for a few minutes (just a few) then rinse and dry and your done. keep it clean, put it in the wort during last 10 or 15 minutes of the boil to sterilize. rinse clean of all residue after each use.

congrats on your new chiller.

also read what john palmer says about cleaning copper - http://www.howtobrew.com/section1/chapter2-2-2.html

First off, welcome to HBT! Hope you enjoy yourself.
I'm not sure what chemicals may have been present in or on your copper, but I can tell you what I've read. Wort can be acidic, so you can count on your chiller coming out of your first bath a little cleaner than it went in. My recommendation? a 24 hour soak in a 50/50% solution of water and white vinegar. The acid will remove most of the crud, then just keep it in a clean place between chills. everything will be fine.

As long as your solder was Lead-Free, you have nothing to worry about.

You mentioned silver solder in your initial post. If it was real honest to goodness silver solder and not the lead free plumbing solder used today, you could have a problem. Some of the real high temp silver solders have some lead or cadmium content, and these are not nice metals to ingest in any form. Acidic solutions like wort may dissolve them off the chiller and they might end up in the beer.

I would figure out what solder was used, and check with the supplier for cad and lead content. You could also sand the remaining solder off the copper, do the acid wash mentioned above, and you'd be okay.

Check the John Palmer "How to Brew" websight for a real metallurgist's point of view.

thanks for the replies...
AiredAle ... it was actually silver solder I use for audio equipment--I'm an audio purist. The composition is 96.5% Tin, 3% Silver, and 0.5% Copper. I was primarily concerned about the tin; I know silver and copper are relatively inert but not sure about the tin and/or flux the solder contains.

I haphazardly blurted off 3/8" when I originally posted. I measured just now and read 5/8" OD. I reasoned that larger diameter tubing would circulate a larger volume of water and have a greater capacity for heat absorption as the tube courses through the wort. This could be entirely erroneous for reasons I haven't considered. Any thoughts?