Line a 1.2 litre pudding basin with cling film, with plenty of overhang.
Remove and discard the stalks from the currants. Combine the fruit, sugar and water into a saucepan and bring to the boil over a high heat, then reduce to simmer for 5 minutes.
Cut away the crusts from the bread, then cut all but one slice in half. Line the base and sides of the prepared pudding basin and press the edges down firmly, reserve the whole one slice for what will be the base.
Spoon the fruit mixture into the basin, reserving some of the cooking juices for serving. Cover with the reserved slice of bread, making sure there are no gaps around the edges. Place a saucer on top and then place a weight on top, this will press everything together. Allow to cool then place in the fridge overnight.
The next day, remove the weight and saucer and place a serving plate on top, making sure the cling film is sticking out the sides. In one smooth, swift motion tightly holding the two together, flip them over so that the pudding basin is inverted over the serving plate. Gently pull on the clingfilm to release the summer pudding from the basin. Once you feel it loosen, remove the pudding basin then peel off and discard the cling film. To serve, slice into wedges and pour over the reserved juice.