Soap As Tarnish Remover

This is a Captain’s Choice heavy copper lather bowl which I use pretty much every shave. It originally had a lacquer coating inside and out but the coating on the inside is long gone. I’ve noticed that some soaps have the effect of removing all oxidation/tarnish from the spot where I smear it into the bowl. Not all soaps do this. The one that did it this time was GD Laundry III which is one of Mo’s awesome Mallard soaps. Some other brands have had this effect also but I haven’t kept track and it’s pretty tough to compare ingredients as the lists on many of these soap’s ingredients lists are long and tiny! Anybody have any ideas on what ingredient might cause this?

Ketchup

Ketchup 

Ha! I remember that discussionthere’s no ketchup in this soap… unless it’s listed under its Latin name.

Maybe the stearic acid amount. Just guessing

Maybe the stearic acid amount. Just guessing

Is the soap acidic or base ph wise?

Maybe the stearic acid amount. Just guessing

Is the soap acidic or base ph wise?

80 Strips Professional 1-14 Ph Litmus Paper Ph Tester Papers Ph Meters Indicator Paper Water Cosmetics Soil Acidity Test Strips https://a.co/d/iY0HAAA

Chelating agents ( i.e. EDTA )  do this.

Google " EDTA and cleaning tarnish " for
example and read for yourshelves.

EDTA and other similar agents are frequently
used in shaving soaps as " water softeners ".

PS : Me thinks that it's kinda difficult for a soap to be acidic .

It’s definitely the ketchup.  Hahaha

I use this chelator "Tetrasodium Glutamate Diacetate"

TGDA (Tetrasodium Glutamate Diacetate) is a much safer ( health-wise) than many other commonly used chelating agents like EDTA .