I take two of @foodgeeks experiments with sourdough and combine them.

"How do milk powders affect your sourdough bread? " https://youtu.be/rOxLmJDYxzc

"How to make sourdough bread more sour | Part 3 | " https://youtu.be/XSczWjWOQBI

I used Foodgeeks master sourdough recipe. https://foodgeek.dk/en/artisan-sourdough-bread-recipe-an-easy-recipe-for-crispy-bread/