Starting a sourdough culture on wholemeal flour

The description and pictures below present how a sourdough culture was started on wholemeal flour. On all days the environmental temperature was around 30 C.

DayDescription
1 Mix 25 gram wholemeal flour and about 25 gram of (bottled) water. The mix is put in an airtight container and closed.
Photos 1, 2, 3, 4, 5.

2 Open the container. There is a slight scent of fermentation. Close the container.

3 Open the container. There is a strong smell of fermentation. Mix with 50 gram (bottled) water and 50 gram bread flour. Cover with clingfilm and let stand in a warm place.

4 Tiny bubbles have appeared.
Photos 1.

From now on the sourdough culture is put on a double-double feeding scheme i.e. the amount of water is double the amount of sourdough culture, and the amount of bread flour is double the amount of water. This feeding is repeated everytime the dough has risen to its maximum volume. And the feeding is repeated until the dough triples/quadruples in about 6 to 8 hours.

Mix 25 gram of the sourdough culture with 50 grams of (bottled) water and 100 gram of bread flour. Put in a cup and cover with clingfilm.

After about 12 hours the culture has more than doubled in size and does not expand in volume further.
Mix 25 gram of the sourdough culture with 50 grams of (bottled) water and 100 gram of bread flour. Put in a cup and cover with clingfilm.
Photos 2.

5 The culture has tripled in about 9 hours.
Photos 1.

Mix 25 gram of the sourdough culture with 50 grams of (bottled) water and 100 gram of bread flour. Put in a cup and cover with clingfilm.

After 12 hours the culture has tripled in size and has started to collapse.
Photo 2.

Mix 25 gram of the sourdough culture with 50 grams of (bottled) water and 100 gram of bread flour. Put in a cup and cover with clingfilm.

After 5 hours the culture has more than tripled in volume.
Photo 3.

Mix 25 gram of the sourdough culture with 50 grams of (bottled) water and 100 gram of bread flour. Put in a cup and cover with clingfilm.

6 The culture has tripled in volume in about 7 hours and is now ready for usage and storage.
Photos 1.

Once the sourdough culture triples/quadruples in 6-8 hours it is ready for use in breadmaking. In order to store the sourdough culture, it can be maintained as a stiff culture or as a liquid culture.