After about a week, the yeast and lactic acid in your starter will have increased hugely and will continue to grow vigorously, signalling that it’s time to start baking. How does this yeast make a ball of dough turn into a loaf of bread? Once all the bread ingredients are completely mixed in, knead the dough for 10 minutes to set the yeast in the starter to work feeding on the sugars in the flour. The starter will then convert the carbohydrates to carbon dioxide, which is what causes your bread to rise when proofing and baking. After the bread comes out of the oven, the yeast molecules die off and leave air pockets behind, creating the soft and spongy loaf we all know and love.
So now that you know the science behind your breakfast, here’s how to make your own starter. That being said, there are many guides online which go much further into detail than I will, so although I give a quick rundown here, I would recommend that you look at some other sources (linked below this article) before starting.
Ideally, you should have a glass jar such as a mason jar, but I keep my starter alive in a mug. To start with, mix 60g of whole wheat flour and 60g of water in the chosen vessel. Cover with plastic wrap and let it sit in a warm spot for 48 hours. Three days later, discard half of the starter and add another 60g each of plain water and flour. Hopefully, you should start to see some bubbles by this point – the starter should have the consistency of yogurt. Every day for the next 4 days, repeat the same process: discard half the starter and add 60g more plain flour and water – this process is called feeding it. By this point, the starter should have doubled in size and be bubbly, frothy and smell acidic but not overly pungent. Finally, transfer the starter to a new clean jar and name it – a crucial step in the starter’s life. To keep the starter going, repeat the process above (discarding and feeding) every day if the starter is at room temperature, or once a week if it is in the fridge.
Now it’s time turn this starter into a loaf. You will need 500g of bread flour, 100g of rye flour, 500mL of warm water, 50g of active sourdough starter (this means it is living at room temperature and you fed the dough 6-8 hours before you started baking) and 10g of salt.
Roughly combine all ingredients except the salt in a large mixing bowl, then tip the mixture out onto a bench and sprinkle the salt on top. Knead the dough for 10 minutes (that’s where those arm muscles will come in), then put the dough into a clean bowl, cover it up and let it rise for 2-3 hours at room temperature. Turn the dough out onto the bench again, knead it once or twice then shape it and place into a bread tin or banneton. Let it rise again overnight at room temperature.
In the morning, preheat the oven to 230˚C, then score the dough by making a few slashes in the top with a knife. Bake for 30-40 minutes, or until the bread sounds hollow when tapped and turn it out onto a cooling rack. Rest the bread for approximately half an hour on the rack before slicing and serving to ensure the crumb of your loaf is fluffy and not soggy. Voilà!
Hopefully, you have whipped up your very own delicious loaf of sourdough – even if it didn’t quite qualify as an artisan bread. However, even if you read this article without baking your own bread, I trust that you now have a newfound appreciation for the scientific intricacies behind the bread at your local bakery.
Links to sourdough starter guides: