Does it matter whether I mix the sourdough with spelt, buckwheat or other flour?Updated a year ago

Your sourdough from Fairment is a rye starter. To maintain its own characteristics, it is fed with wholemeal rye flour. However, you can also easily convert your sourdough to other types of flour.

Basically, all types of flour from cereals are suitable: If you regularly feed your starter with whole wheat flour, you will have a typical wheat sourdough. Gluten-free flour made from brown rice, teff or buckwheat can also be used for sourdough feeding. So with your one starter you can grow a whole range of different types of sourdough. After one or two feedings with the new flour, the sourdough has usually changed and taken on its own characteristics. In contrast to rye wholemeal flour, other types of flour are best used 1:1 with water, e.g. both 80g. 

We recommend that you ideally feed your starter continuously with one type of flour and not change it every time you feed it. So if you want to have several types of sourdough available, just make a few offshoots so that you end up with several starters. This way the microbes can get used to their particular food and don't have to change with each feeding.