It is generally best to start a new culture with wholegrain or organic rye. These flours are full of naturally-occurring enzymes and nutrients that encourage microbial populations to grow. It is however easy to convert your established starter to another flour, you simply refresh using the new flour. The advantage of using white roller-milled flour is it takes longer to peak because the microbes have to work harder for their food. You can use this to your advantage, especially when you are planning a bake to fit in with a schedule to suit you.
