Why can it be assumed that coffee from coffee shops is kosher? Why couldn't the equipment become unkosher through exposure to non kosher ingredients or when being cleaned?
For example the Canadian chain Tim Horton's makes coffee in pots and puts those pots in a non kosher dishwasher. To me that should make the coffee not kosher.
There's also the issue with stirring milk/sugar with a non kosher spoon.
Why do (a significant number) of kosher Jews assume all this is kosher?