And so I continue my sourdough journey. My obsession with wild yeast cultures driving me to make endless amounts of yeasty breads, cakes and buns. What’s wonderful about sourdough is that each jar of trapped culture has its own personality; smells, textures, tastes. Each needs to be fed at different times, can be both docile and energetic, a help and a hindrance. And unlike its industrial cousin – commercial yeast – it cannot be relied on. You have to check it before you add it to your mix, make sure its active and working, ready to start fermenting your dough. It makes each bake an adventure.
Both my cultures lie dormant in the fridge until needed – Calvin, named after the comic character not the religious nut, and Astral, my daughter named her after a character from Harry Pottter – and both have worked hard for me. I look after them, feed them, check up on them, and they do all the heavy lifting when required.
Last week I thought I’d try making a traditional German yeasted plum cake using Calvin. The recipe calls for commercial yeast but I thought I’d try and make a sourdough variation. So if you’re interested in taking a step back in time make some sourdough and get baking otherwise use commercial yeast as directed. I’ve given you both versions below.
These German Kuchens are delicious and feel free to swap out the fruit for whatever is in season. To be honest they’re not quite a cake nor are they a tart. They’re not sweet either so are perfect with a big dollop of sweetened cream for afternoon tea. We had ours after Sunday dinner. Not an appropriate time really. Next time it’ll be with a cuppa tea. This version is based on a riff David Lebovitz did on an original recipe by Luisa Weiss, author of the blog, The Wednesday Chef.
Just a note on the sourdough conversion. I was advised to approach it using a 1.2.3 formula. A 100% hydration starter = 1/6 of the dough. So if you’re converting any yeast recipe you simply add up the total liquid and flour and divide by 6. This gives you the starter amount. You then divide starter (its only flour and water) by two and subtract those amounts from existing liquid and flour in recipe. And off you go. And remember sourdough takes longer to work its magic so be prepared to give your dough more time to rise. Does that make sense? If not you can always google an alternative explanation or reach for the fast action yeast in your cupboard.
Dough and plum topping
225g (195g if using sourdough) flour
2 teaspoons active dry yeast, 14g fresh yeast, crumbled or 60g 100% hydration sourdough
125ml (95ml if using sourdough) whole milk, divided
3 tablespoons sugar
1 large egg yolk
3 tablespoons melted butter, cooled to room temperature
pinch of salt
grated zest of one lemon
700g Italian prune plums, pitted and quartered (or whatever is in season)
50g sliced almonds
70g light brown sugar
2 tablespoons granulated sugar
1 teaspoon ground cinnamon
55g unsalted butter, cubed, cold
Butter a 23cm springform pan.
Add the flour to a mixing bowl and make a well. Add the yeast and half the milk as well as 3 tablespoons of sugar. Mix the liquid ingredients with a spatula, incorporating just enough of the flour to make a wet paste. Let sit for 15 minutes or up to 30 if you’re using sourdough.
Stir in the remaining milk, egg yolk, 3 tablespoons of melted butter, salt, and lemon zest and mix everything together well. Knead the dough on a lightly floured surface until smooth. Shape the dough into a smooth ball and put in the buttered cake pan. Cover with a kitchen towel and let rise in a warm place for 1 hour, until doubled. In the case of sourdough this will take longer so keep an eye on it.
While your dough is rising, make the streusel topping by putting the almonds, flour, sugars, cinnamon and salt into a food processor and pulse until the almonds are broken up. Add the butter and salt and process until the mixture first becomes granular and then begins to clump together. It takes a few minutes so don’t panic. It will clump.
When your dough has risen use your fingers to smooth it across the bottom of the pan and about a 3cm rim up the sides. Place concentric rounds of prune plum wedges over the dough, within the rim, pushing them close together.
Strew about 120g of streusel topping over the top – and be generous I was a bit mean thinking it was going to be overly sweet and held back. The result was a tart tart. Let the dough rise for at 20 minutes. Preheat the oven to 350ºF (180ºC).
Bake the tart for 45 – 55 minutes or until the streusel topping is golden brown. Remove from the oven and let cool.
This is the kind of cake/tart/whatever that’s best served and eaten on the same day. Next day at the latest so if there’s spare going take it next door.