Your starter should not smell horrid at any time, or have black bits in it, or indeed any mould whatsoever. On a rare occasion you may have a good go at making your own starter only to find it smells or tastes horrid, or that the bread and other baked goods it produces aren’t all that pleasant. This means the bacteria that has occupied your starter is not the right kind and the lactic acid, which makes the starter inhospitable to other organisms, hasn’t got going. You will need to discard this starter and start over. This time move the location of your culture to a different room.
I most often find when I talk to people who are having difficulties with bad smelling starters, they are not refreshing often enough. You need to refresh daily when you are starting a new culture, and you must refresh regularly when maintaining it. Once a week is the ideal.
If you are just getting a starter going, do not use hot water because this can kill the microbes you are trying to culture . Use warm water at about 27 degrees C. And there is absolutely no need EVER to add any bakers yeast.
Sometimes using fruit can introduce live yeast and other bacteria especially on grapes, but to be honest the yeast you want to encourage is on the outside of the grains. It is naturally present in the grain that you use. For the best results, use stoneground organic wholemeal flour, because the milling process is at a much lower temperature so the yeasts will survive.
