[soymateofeo]

I use a copper immersion chiller as a herms coil.  I clean it before each use with pbw and starsan or saniclean.  Will pbw alone get rod of any green copper. I am wonderjngvif the starsan is overkill.  Or maybe the pbw is not necessary? What say you?  I do not want toxic green copperness in my brew.

[Slowbrew]

In my experience a good soak in Starsan has also done the job.  I haven't used PBW on my chiller.  I would think either/or but you don't need both.

Paul

[Kevin]

I circulate hot water with PBW in it OR boiling water. Starsan is not a cleaner. You must clean before you can sanitize.

[Visor]

^^^^ this, you can't sanitize crud.

[kramerog]

A little PBW and some elbow grease is a good way to remove the green stuff.  I wouldn't use starsan as that will dissolve the oxidized copper.  I think the dull copper is pretty insoluble so that is the preferred appearance for your chiller/coil.

[ynotbrusum]

Every few months I do an extended (2-4 hours) hot water and alkaline cleaner re-circ of my HERMS and counterflow chiller to be sure nothing too nasty is lurking on the interior of the pipes and to help assure that I am getting good cooling efficiency without beerstone - but I use a stainless system, so I don't have the copper green issues....then maybe once a year, I will follow up with an extended starsan recirc after thoroughly rinsing out the alkaline cleanser.

[Kevin]

A little PBW and some elbow grease is a good way to remove the green stuff.  I wouldn't use starsan as that will dissolve the oxidized copper.  I think the dull copper is pretty insoluble so that is the preferred appearance for your chiller/coil.

The OP is talking about cleaning residual wort from the inside of a HERMS coil.