Firstly, we will make tangzhong (aka water roux or Mehlkochstück in German). In a small pot, pour in water and add in whole grain spelt flour. Over medium heat, cook and stir the ingredients continuously until a gelatinous mixture is formed.
Turn off heat and let the Tangzhong cool down completely.
In a small bowl, add in warm water, whole grain spelt flour, the water roux and the sourdough starter (according to the given order and sterilize your spoon with hot boiling water before taking the sourdough out of your container). With such a small amount of ingredients, it is easier to mix the ingredients with your hands. If you are using an electric mixer, mix the ingredients at the lowest level for about 3-5 minutes until you get a dough.
Spread some all-purpose flour in another small bowl and transfer the dough into the bowl. If the dough is sticky, simply spread some flour on your hands.
Cover the bowl with a suitable cover, cutting board or a plastic to prevent the dough from drying. Thereafter, keep the bowl in a warm place (about 21 °C - 26 °C). The sourdough will work faster in a warmer place.
After 2 - 8 hours, check if the bread dough has increase in size (it does not have to be double). Once it has increase in size, stretch and fold all sides of the dough with a dough scraper. If you do not have a dough scraper, you can use an old credit card which is no longer activated. If the dough gets too sticky, dip the dough scraper into a bowl of water or spread very little all-purpose flour to ease the folding.
After which, cover the bread dough again and repeat step 5. Once the sourdough bread rises for the second time (it should double in size) after about 2 - 8 hours, repeat step 6 and 5 once more.
When the dough rises for the third time after 2 - 6 hours, spread a little flour onto your working space and transfer your sourdough bread from the bowl to your working top using your dough scraper. If the dough gets too sticky, dip the dough scraper into a bowl of water or spread very little all-purpose flour to ease the folding.
Do not knead the dough so that we can retain the air in the bread, simply form the dough into a round shape. If the bread dough gets too sticky, spread a little flour onto your hands.
Place a kitchen towel in another small bowl and distribute a little flour all over the towel to prevent the dough from sticking to the towel. For one last time, repeat step 5 for another 1 - 2 hours.
Preheat baking oven and cast iron pot with a lid to 250 °C. Once the oven is hot enough, take the pot out. Be careful, it is extremely hot! If you do not own a cast iron pot with a lid, then please refer to this post for an alternative baking method (from step 9 onwards). Remove the cover of the pot and transfer the bread dough onto the parchment paper by simply grabbing the kitchen towel and bowl. Flip the bowl and the dough will drop onto the baking tray. Use a knife to score the surface of the bread and spread a little flour over the surface of the bread for a rustic look.
Cover the pot with a lid (be careful, it is hot!) and place everything into the preheated oven. Lower the heat to 230 °C and bake for about 15 minutes.
After 15 minutes, remove the lid of the cast iron pot and continue baking the whole grain baby spelt sourdough bread for about 10 minutes or until the bread turn brown/ crispy. It depends on your baking oven, you might need to adjust the baking time accordingly. Just have fun and try it out.
After baking, remove the sourdough bread for baby from the tray and place it on a cooling tray until it is completely cool down. Thereafter, you can store it in a cloth bag. Serve this bread plain or with some homemade baby fruit jam for breakfast. Finish it within 3-4 days.