While we're on yeast and fetal tissue, here is a link to an article by the vegan society, concening the use of bleached animal bones in processed sugar: https://www.vrg.org/journal/vj2007issue4/2007_issue4_sugar.php
"In 1997, The Vegetarian Resource Group published an article on sugar refining, focusing in particular on the char derived from cow bones that is used as a filter to whiten cane sugar during the refining process. In this report, The VRG revisits the issue of bone char use in the sugar industry, examines emerging practices for refining sugar, and discusses alternatives to sugar refined with bone char."
You know where I'm going with my thinking here. If animal bones, then why not human bones? How the hell do we dig this one?!?