Mommy, you made a google loaf! These were the words of my daughter when she saw this cake followed by a nice laugh together.
I've done sweet dough with sourdough before by transforming recipes based on baking powder into sourdough-based ones. Nothing new here but it is the first time I have followed a professional recipe. This actually comes to add pieces of knowledge to my quest to understand more about these mysterious creatures generically called sourdough.
I've also had a quest in perfecting recipes based on baking powder but I found a few disadvantages that almost made me give up.
The first is the fact that all rely on the chemical reaction in the oven. There is no way to guess its behaviour in the oven only by looking at the dough before. Will it rise enough? Will it crack? Will it be soft inside? With sourdough, the dough is already well-risen when the dough is put into the oven and this gives a good prediction about what you'll gonna get.
The second thing that I do not like is that the baking powder-based cakes deflate slightly when taken out from the oven. This never happens visibly when the dough is based on sourdough.
There are disadvantages to baking with sourdough too: it takes time and you may get it sour! Unlike bread dough, where you need to perform a series of steps, this dough is mixed, let to rest for 30 minutes, and then left alone to rise overnight in a warm place. The used starter is not a liquid one but a stiff one. Although you can quickly transform a liquid starter into a stiff starter in only one step this is not enough. There is a reason why pasta made is used for sweet dough: it reduces acidity. Pasta made has its own preparation steps in order to get it right for the dough and this actually takes one day: start with a sourdough bath, to reduce the acids, then feed it 3 times at shorter intervals (kept at warm temperature) to get it very active.
This was my first trial to get it properly done (in line with the indications) and I did my best to align. The ph of the starter I did not get it right during the feeds, I'll need to tinker with some methods/temperatures to get it perfect next time.
Analysing the cake, here are my thoughts: the rise was good but I believe there is a place for better; the taste was interesting and nice but I detected a bit of sourness that shouldn't be there. The cause is still related to the power of the starter to rise the dough and temperature.
If you want to know the original recipe, I invite you to check the book "Coffret Traité de boulangerie au levain" by Thomas Teffri-Chambelland. I have the French version but I understood there is an English version too. Please note that this book is not for beginners... it's about the science of baking and there are a few recipes presented too. But if you are a sourdough geek, I can only recommend this book(s). No hidden publicity here, just my honest opinion as a homemaker with a passion.
I will test more recipes with sweet sourdough in the future although clearly not as often as I'll do for bread. For this recipe, I'd make a few more adjustments to make it perfect but I have to tell you that my kids loved it as such. Here is the recipe: