Silver, steel, tinned copper and enamel

Four metal vessels with four different relationships to heat and to the liquid inside them. A metallic taste in tea is nearly always traceable to one of these, and which one tells you whether it is fixable.

equipment

What is being compared

Why these get confused

'Metal teapot' is treated as one category with one set of properties, usually 'conducts heat and might taste of something'. Four different metals with four different linings behave four different ways, and only two of them can go wrong chemically.

Point by point

AspectSilver teapotStainless steel teapotCopper and brass teawareEnamelled steel teaware
What it is made ofSterling or fine silver, or silver plate over a base metal.Stainless steel, single- or double-walled.Copper or brass, traditionally with a tinned interior where it holds liquid.Pressed steel with a fused glass coating on both faces.
Heat conductionThe best of any common vessel material — it heats through instantly and loses heat to the room just as fast.Single-walled sheds heat quickly and becomes too hot to hold; double-walled does the opposite on both counts.Better than steel, which is why it was the material for samovars and urns.Conducts through the steel; the coating is thin and does not insulate.
What the surface does to teaNon-porous and takes up nothing.Inert.Copper reacts with acidic liquids, which is why the interior is lined.Glass, so inert and easy to clean.
The failure mode to check forPlate wearing through to base metal.None chemically. The failure is thermal — a single-walled pot burning your hand.The state of the tin lining. Worn tin exposes bare copper to the drink.Chips. A chip exposes bare steel, which rusts and spreads under the surrounding enamel.
If the tea tastes metallicSuspect plating wear.Suspect the kettle or the water, not this.Suspect the lining first and always.Suspect a chip, and look under the rim and around the spout.
Practical verdictExpensive, and the thermal behaviour is a real trade rather than a pure advantage.Double-walled steel is the honest workhorse for a pot that must stay hot.Beautiful and serviceable if the lining is sound; a job for someone who will check it.Cheap, durable while intact, and finished the moment it chips.

The short answer

None of these is inert by virtue of being metal. Silver and stainless steel genuinely are; tinned copper is inert only while the tin is there, and enamel only while the glass is unbroken. That is where the difference lies and it is a maintenance question, not a materials question.

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