Originally Posted by MachineShopBrewing
This is true to an extent. However this generally won't happen unless you keep liquid in your equipment for long periods of time. Especially with Copper up against Stainless steel.
The key for us, if I understand this right, is the length of exposure. Short-term exposures (such as a 1 hour boil or 1.25 hr. mash) reduces the rate of corrosion.
And the next question is, so it corrodes a little. What harm is there in it? Does this minimal corrosion release anything harmful? If it does, is it at a level that we need to be concerned about it?
Doesn't a lot of this concern originate from a time when roofers used to stuff a bunch of galvanized nails in their mouths and did it day in and day out? The proportion of exposure is, IMO, significantly different.