Earlier quoted context omitted.
> modern packaging But the packaging itself matters, eg soda in a Al can and a glass bottle is perceived quite differently. If the milk came in a plastic bottle I have no problem drinking directly from the bottle, if it came in TetraPak... If I bothered to cut it with scissors I would probably be fine drinking milk directly, but if I just ripped the corner by the perforation then I would definitely drink from the mug…
Just an FYI, but aluminium cans are lined with a plastic lacquer - so what you are tasting isn't from metal.
Still, my lips are on the can and if I fill the glass from the said can it tastes more "glassy" than "metallic".
As a sibling comment says - it's all in our heads *shrug_emoji*