Question: We bought two new plates to replace ones which had smashed from our set. We accidentally put them in the cupboard with the others before tovelling them and don’t know which ones they are. What should we do?
Answer: The Shulchan Aruch (YD 109:1; 122:8) writes that if a forbidden item such as a dish gets mixed into a pile of similar items that are permitted, then it is battul berov, annulled against the majority, and thus, permissible.
Nonetheless, R’ Chaim Falagi (Ruach Chaim YD 122:1) and R’ Tzvi Pesach Frank (Har Tzvi YD 93) write that this rule doesn’t apply to our scenario. The Shulchan Aruch (YD 102:1) writes that something that can be rectified (davar sheyesh lo mattirin) isn’t even battul if mixed into a thousand parts. However, this only applies to something that will either inevitably become muttar with the passage of time or if it doesn’t involve a big expense. Thus, a treif pot that got mixed into a pile of similar pots will be okay to use as it is costly and cumbersome to kasher all of the pots (See Chochmas Adam 53:23). As it isn’t such a bother or expense to tovel a few dishes, however, one needs to tovel them all.
R’ Falagi writes that as one of these dishes will inevitably be the non-tovelled dish, one should say a beracha when tovelling them (See Shevet Halevi 4:93; 6:37:2). R’ Frank, however disagrees, writing that this scenario is similar to separating terumos and maasros from demai in which case one doesn’t say a beracha.
R’ Eliezer Waldenberg (Tzitz Eliezer 11:58) and R’ Ovadia Yosef (Yabia Omer 2:YD:9:4) challenge this, explaining in depth why the rule of davar sheyesh lo mattirin doesn’t apply to kelim that may not have been tovelled. Thus, R’ Waldenberg writes that if it’s at all a bother to tovel them, then one doesn’t need to.
In conclusion, if a dish that wasn’t tovelled got mixed into a set of dishes that was tovelled, one should ideally tovel the whole set, especially if they live close by to a mikva though one wouldn’t say a beracha when doing so.