Finding it hard to sleep or just insanely fascinated by bread making literature? Either way, this one’s for you. So, grab your favourite cuppa and let’s get into it.
If you recall in Sourdough 101, sourdough is believed to have been developed by those wily Egyptians about 6000 thousand years ago. No one knows for sure, but it may have been discovered accidently when a dude (or dudette) left a bowl of flour and water lying around only to observe the foaming, frothing liquid formation several days later. Chances are the person used that excess liquid – waste not, want not – and added it to the fresh batch of dough and so the birth of sourdough bread was complete.
Unbeknownst to the unsuspecting baker, that foaming liquid concoction would ultimately revolutionise mankind’s eating habits. It turns out there is yeast floating in the air we breathe. Once this wild yeast makes its way to the flour and water mixture called the “starter” (the term “leaven” is often used interchangeably), it starts growing and dividing.
The function of yeast is to break down the starches in wheat flour and convert them to glucose (sugar). This process is called “fermentation”. When the yeast works off the starch and sugar molecules, it releases carbon dioxide gas and alcohol. Yeast is effectively the leavening or rising agent for the bread.
Wheat flour contains two types of protein called “gliadin” and “glutenin” which form a stretchy substance called “gluten”. When you knead the dough, you help gluten form long thread-like chains which hold the carbon dioxide gas in the dough which, in turn, creates those beautiful air pockets in the bread.
So, I’m guessing you now know the difference between sourdough bread and “commercial” fast baked bread? That’s right. It’s the yeast. In the fast baked bread, yeast comes in compressed or powder form created in laboratories hence packaged. Sourdough uses the natural yeast which is kept alive in the liquid medium called the starter. The starter is then “fed” every 24 hours or so, with more flour and water until it becomes frothy and gooey (not to mention a little smelly). That smell is the indication that the yeast population is growing. The regular feeding or replenishing is what keeps the yeast “culture” alive. The froth is caused by the carbon dioxide generated by the yeast. The starter will also contain good bacteria called “Lactobacillus” which creates lactic acid. Remember, the yeast also creates alcohol. The combination of the alcohol and the lactic acid is what gives the dough the slightly sour and unique flavour. Hence the term “sourdough”.
Managing sourdough is often a difficult and time consuming process. The starter and the actual dough itself are sensitive to temperature, humidity and time. We are constantly checking and testing the dough to ensure it is working properly.
It does take time but, as we mentioned before, all good things take time and sourdough served straight from the oven is DEFINITELY worth the wait!