Traditional Polish wheat-rye sourdough bread (recipe in English)

I tried to make this type of bread many times and I was not particularly happy with the results until yesterday I met the baker who explained it all to me. The recipe is from him :)  This is not perfect yet, the crust should have a characteristic dicing, but it depends a lot on the baking conditions, amount of steam at the beginning and starch jelly, brushed before baking.
Very yummy, aromatic, light and fluffy with a crunchy crust. Not complicated, worth trying.
Please pay attention, that in this bread, properly refreshed, mature sourdough is the basis of the aroma and proper bread structure.

Ingredients for the dough: 

333 g wheat bread flour
183 g water
8 g salt
4 g fresh yeast

166 g rye sourdough (50% hydration)

The most important thing in this bread is properly refreshed sourdough!
I made the refreshing of rye sourdough in the following way:
I set the 1st phase at night and left till the morning: 10 g rye sourdough from the refrigerator / 20 g water / 20 g light rye flour , 9 h 24-26C
2 phase then I took from this 34 g / 17 g water / 34 g light rye flour 3,5 h 26-28C
3 phase then I took from this 80 g / 40 g water / 80 g light rye flour 3,5 h 26-28C

dough approx. 690 g

Mix slowly 10 minutes, then quickly 2 minutes or unless your hands hurt you, salt at end of mixing.
Let it bulk at 26C 20 minutes, degass, wait next 20 minutes, preform the ball, wait 5 minutes and shape the bread.
Final proof  in the benetton 45-60 minutes
Before baking, brush the loaf with potato starch jelly.
Bake about 45 minutes at 200C, steam in beginning of bake.

Enjoy :)

Some photos:

sourdough phase 1

sourdough phase 2

sourdough phase 3

premixed water, yeast, sourdough phase 3

kneaded dough

preformed dough

formed loaf