1.Preheat oven to 180°C (160°C fan-forced).
2.Grease a 14cm x 21cm loaf pan; line base and long sides with baking paper, extending paper 5cm over sides.
3.Beat butter, sugar and rind in a small bowl with an electric mixer until light and fluffy. Beat in eggs, one at a time, until combined. Stir in flours, sour cream and juice, in two batches. Stir in currants. Spread mixture into pan.
4.Bake loaf for about 1 hour 10 minutes. Stand loaf in pan for 10 minutes before turning, top-side up, onto a wire rack to cool.
Loaf can be stored in an airtight container for up to 3 days.Note