There are several non-Jewish owned fruit trucks near work. Occasionally, the non-Jew squeezes grapes to make fresh grape juice. I understand that the grape juice prepared by a non-Jew is non kosher.
However, after he squeezed the grapes for another customer, can I get other fruit juice from him? Does his squeezing the grapes make the juicer non-kosher? If so, can I get juice if the owner rinses the juicer?
Disclaimer - I asked my rav about the general use of getting juice from a street vendor who does not use grapes. He said that providing that the only thing made is from fresh produce and the knife and cutting board is used only for that purpose, there is no problem.