Recently, we are getting issue with the yogurt. Light brown grainy layer, some kind of sediment is seen at bottom of the yogurt. To brief the process, we started using skim milk to standardized the whole milk, so in turn to increase the total solid content we increased the qty of skim milk powder & also we are homogenizing after adding skim milk powder to the milk. I guess this might be due to improper hydration. I don't understand where I am processing wrong. Any help will be appreciated.