Let there be life: creating your own starter

Currently I have a really enjoyable work project on the go, editing a cookery book, but while I've been waiting for copy to come in, I've been doing a lot of baking. I've also been trying to create a leaven. A week on, it seems as though I may have succeeded with my leaven as it truly seems to have come to life. It is VERY exciting.

Last Tuesday, following Dan Lepard's instructions in The Handmade Loaf, I mixed together wholemeal flour, strong white flour, live yoghurt, raisins and water. The pictures below are before and after mixing (day 1) and leaving it in the sealed Kilner jar.

Each subsequent morning this was fed with flour and water and yesterday (day 7), after feeding it, I strained the starter and returned it to the jar. This morning I discarded three-quarters of it, fed it and, within a few hours, it sprung back to life. Earlier this afternoon, I look up from my work and saw the starter almost filling the jar, bubbling away (see below and first picture). Over the course of the week, the aroma became more acidic, yesterday it was more like fresh bread and now it's a subtle rotting apple smell. You really can't believe your eyes when you see all the activity.

I might even be able to bake my first sourdough loaf later this week which is a particularly exciting thought. The wonder of nature!