Preheat the oven to 375 degrees. Line a baking sheet with parchment paper.
Combine the 4 cups of flour, sugar, salt, and baking soda together in a bowl of an electric mixer fitted with a paddle attachment (or a hand mixer will work too).
Add the butter and mix on low speed until the butter is mixed into the flour.
Whisk together the buttermilk, egg, and orange zest in a separate bowl until very well combined.
Slowly add the buttermilk mixture to the flour mixture and mix until just combined.
Add a tablespoon of flour to the dried currents and mix until evenly coated. Side Note: This step helps ensure the currents won't sink to the bottom of the loaf while baking.
Fold the dried currents into the dough until evenly combined.
Dump the dough out onto a floured board and knead it a few times into a round loaf.
Place the loaf on the prepared baking sheet and lightly cut an x into the top of the bread with a serrated knife.
Place into the oven and bake for 45-55 minutes, or until a cake tester inserted in the center comes out clean. When you tap the loaf, it should have a hollow sound.
Cool on a baking rack. Serve warm or at room temperature. Enjoy.