I’m a bit obsessed with this cookie.
A few days ago I saw Edd Kimber post on Instagram about using sourdough discard in cookies and I was immediately intrigued. The main reason I’m put off keeping a sourdough starter at home is that I usually don’t have enough time to bake bread every week, so I end up using up a lot of flour to keep it alive but don’t do enough with it. Luckily though, my housemate has been keeping a starter due to all of the extra time we have at the moment.
When I heard about this ingenious way of using sourdough discard, I couldn’t wait to try it out myself. The science behind it is all about water levels in the recipe. 100% hydration sourdough starter is 50/50 water and flour. So for example; if you add 200g of sourdough starter into a recipe, you need to take 100g flour and 100g water out from the original. Flour is easy to simply re-calculate but water is a little more difficult.
I decided to try and adapt Sarah Kieffers iconic ‘pan-banging cookies’. My perfect cookie is crisp and rippled around the edge with a soft centre (which is exactly what this recipe provides.) There are a few ingredients in this cookie recipe that contain water. Firstly; the extra added water, then the egg and finally the butter. In order to add in the starter and its water I took out the original added water, the egg white and browned the butter to evaporate off the water. This all together gave me 100g of water to add back in which meant I could use 200g of sourdough starter. A great amount to use up and enough to impart a lovely flavour.
I also played around with the quantity of salt, sugar and chocolate chips as well as the size and method. It ended up not really resembling the original recipe but I am so happy with the results.
These beautiful cookies are a wonderful mix of nutty brown butter flavour, flaked sea salt and warm oozing dark chocolate. By banging the cookies halfway through baking, they purposely fall and create beautiful ripples along the edges. I’m always thinking about what a ‘perfect’ cookie would be to me, but I’m pretty sure its right here.