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?