How is batel beshishim verified practically?

Question

I understand the general rule that if there is a mixture of meat and milk and the meat is < 1/60 of the milk it is a dairy product, or if the milk is < 1/60 of the meat it is a meat product.

If one watched the quantity of milk or meat go in, and it is a small amount compared to the volume of the other, one could most likely conclude batel beshishim. How does one determine this if he has no idea how much went in, but was informed by someone else or suspects that it may have occurred?

Someone told me that one should taste the product and if he detects a meat taste in what appears to be a dairy product, then it is not batel beshishim. The problem with this is that everyone's taste is different. What happens if two people taste the same item and you have conflicting opinions? How do you determine what to do?

Answer 1

In general Askenazim follow the Rema and do not rely on someone tasting it. See here and here

If the question is about a mixture that would be forbidden m'dioraisa if it is not batul in 60, then we assume it is not batul. If it is a question of a d'rabonon, like milk in chicken, then in many cases you can assume there was only a small amount and it is batul. See Chochmas Adam

If a Jewish expert קפילה would taste it and tell us it does not have a taste of milk, we would be able to rely on him, but the technicality here is, how did he get to taste it? [See Shach 98/5]

There is a chiddush from the Teplika Rav [the one that taught Rav Elyashiv and Rav Ovadia Yosef], at least by a great loss and big need, that a non-Jewish expert can be relied on by Sefardim. Then a Sefardi can tell the Ashkenazi if it has no taste of milk [or whatever issur it is that fell in]. [See אהל יעקב איסור והיתר סי' צח הערה א]