I experimented with Faffas best yoghurt recipe (
http://www.forumthermomix.com/index.php?topic=10188.0) making vanilla bean yoghurt last night. I only did 1/2 the recipe, because I didnt want to waste the milk if it didnt work. I sliced open a vanilla bean and put the seeds into the milk, then dropped in the bean as well for the first 20 minutes of heating, and for the cooling time. I took the bean out just before adding the cultures, and left overnight as usual in the thermoserver wrapped in a blanket.
This morning - beautiful, thick, creamy vanilla yoghurt that was not overpowering in flavour (but definitely noticeable!) and not overly sweet like the commercial varieties of vanilla yoghurt. You could add honey or agave if you wanted it sweeter though.
Am thinking of trying with lemon myrtle leaves next time .......