Can we reasonably determine whether a product contains unclean ingredients simply by looking at the label or calling the company? There are three major issues with this practice. For these reasons, I strongly advise we look to credible kosher certifications when we buy food products.
[Aleksandr Sigalov:] Please note that kosher certification agencies have their own share of the problems (i.e insects or agents), therefore please still be careful when choosing a product. It is always good to double check with the agency and the manufacturer about the ingredients.