I am a newy to this forum but my daughter and I have been making yoghurt in our Thermie regularly, at least twice a week for over 4 years without a failure BUT the last three my daughter has made have not set, can anyone please throw a light on the problem?? We use the similar recipe, I do 800mls full cream milk, 50grms powdered milk, heat at 90 for 10 mins., cool until 37 add 3 tablespoon of previous yoghurt 'cook' for 10 mins at 37 allow to set in easiyo equipment (prewarmed) for at least 6 hours and always sets perfectly, my daughter does almost the same except she has NEVER included powdered milk but she heats at 90 for 20 mins, the rest the same as mine, until the last three no dramas HELP please