Question: May one drink coffee in a friend’s home or in a Café (such as an espresso without milk served in Cafes) when they are not meticulous about immersing their vessels in a Mikveh?
Answer: In the Halachot discussed before Tisha Be’av, we have explained that vessels produced by non-Jews must be immersed in a Mikveh. We have also written that it is forbidden to eat or drink from vessels or dishes which have not been immersed.
On the other hand, we have written in the past in a Halacha discussing drinking coffee brewed by non-Jews that if there is no Kashrut concern with the coffee served on the airplane, one may drink the coffee and there is no concern of “foods cooked by a non-Jew.” We must now discuss the issue of the coffee being served on dishes which have not been immersed.
When the Owner of the Establishment is a Non-Jew
We must first point out that the question only begins when the owner of the restaurant or café is a Jew who has not immersed the vessels in his possession. However, if the owner is a non-Jew, a non-Jew is not obligated to immerse his vessels in any case. Even if he would immerse the vessels, this would do nothing at all. One who drinks in a non-Jewish-owned café need not have the vessels immersed since he has not purchased the vessels and they are merely lent or rented to him. In such a case, there is no obligation to immerse the vessels at all.
We must therefore only discuss the law regarding a Jewish-owned café or airline where the vessels in their possession are not immersed.
Maran Rabbeinu Ovadia Yosef zt”l deals with this issue in his Responsa Yechave Da’at (Volume 4, Chapter 44) and we shall now mention his fundamental points:
Vessels Purchased for Commercial Use and not for Personal Use
Firstly, if one buys vessels from a non-Jew for commercial purposes and not in order to eat with them personally, one need not immerse the vessels in a Mikveh. Thus, Jewish store-owners who purchase vessels from non-Jewish companies and later sell these products to Jews need not immerse the vessels in their possession, for they are merely used for business purposes, not for eating.
Based on this, since the restaurant/café or airline owner is only purchasing these vessels for his business in order to serve his customers food and drink, it is considered that the owner of the establishment is purchasing these vessels for commercial and not personal use. A customer who eats there is considered either borrowing or renting the vessels, in which case he may eat and drink with these vessels and dishes without them having been immersed.
Thus, the customers need not immerse the vessels themselves since they are merely borrowing or renting them (not purchasing them) and the owner of the establishment need not immerse them, for he has purchased them for commercial, not personal, use. These vessels may therefore be used without immersion.
One who is Hosted by An Individual who has not Immersed his Vessels
Nevertheless, if one is a guest at an individual’s home and knows that the host has not immersed his vessels in a Mikveh, one may not eat and drink off the host’s vessels and dishes until he immerses them since the dishes were purchased for personal use of eating and drinking.
Summary: One may eat in a kosher establishment (or any other place where the food served has no Kashrut concerns) even if the vessels and dishes have not been immersed in a Mikveh. However, if one is a guest in a friend’s home and knows that the host has not immersed his dishes, one may not eat anything off of his friend’s dishes, even if the foods themselves pose no Kashrut concern.