For rye breads, you should make the sourdough as follows:
Stir rye flour and water in a tall, narrow saucepan (preferably an earthenware pot, no metal!) to make a creamy paste. Add the buttermilk and the dough will ferment faster. Cover the pot and keep it warm, e.g. on the radiator. Stir once in the morning and once in the evening. On the 3rd day it throws bubbles and ferments. In the evening of the third day, add the following ingredients: Rye flour type 1370
Water (35-37 °C) in the ratio 2:1 The sourdough must now be viscous to medium solid. Cover the container again and put it on the heating. Or leave in the oven at about 30 °C until the next day.
For 600 g of sourdough, use the following quantities:
(1 third of the sourdough = 200 g).
100 g rye flour
approx. 100 g water
for the leavening on the evening of the third day you need another 400g.
260 g rye flour
about 140 g of water.
The instructions for sourdough preparation may now be a little confusing for you. But do not worry – it is quite simple. And if you make more on the spot the first time, you can save yourself a lot of work the next time. Because you can keep the leftover sour in a ceramic bowl with rye flour with the lid closed. In the refrigerator for a good 1 week. And then you only need to pour water accordingly on the eve of the next baking day.