Bring half of the fruit and all of the sugar, lemon juice, wine and water to a simmer in a pan. Continue to simmer for 4-5 minutes, stirring regularly, until the berries have softened and the sugar has dissolved.
Transfer the cooked fruit to a sieve using a slotted spoon and strain any liquid back into the pan. Set the drained fruit aside.
Bring the fruit juice mixture to the boil and cook for 20-25 minutes, or until the volume of liquid has reduced to a syrup.
Strain the syrup mixture into a clean pan, reserving 200ml/7fl oz of the strained syrup in a separate bowl.
Return the cooked fruit to the pan containing the fruit syrup. Set aside to cool.
When the syrup and cooked fruit are completely cool, add the remaining (uncooked) fruit and stir well to combine.
Line a 1.8 litre/3 pint pudding basin with 2 large sheets of clingfilm (the edges of the clingfilm should hang over the top of the basin so that they can be used to cover the base of the pudding).
Cut 10 of the bread slices into two equal-sized rectangles. Thoroughly paint one side of each bread rectangle with the reserved 200ml/7fl oz of fruit syrup.
Using the open end of the pudding basin as a template, cut a disc from one of the remaining whole slices of bread and paint one side of it with the fruit syrup.
Using the base of the pudding basin as a template, cut a disc from the remaining whole slice of bread and paint one side of it with the fruit syrup. (Reserve any remaining fruit syrup.)
Put the small bread disc, painted-side down, into the base of the pudding basin. Arrange the bread rectangles, painted-sides down, around the insides of the basin, overlapping the slices slightly where they join.
Fill the pudding basin with the mixed fruit and top with the remaining large bread disc.
Draw the excess cling film layers over the base of the pudding until it is completely sealed. Place a small plate on top of the pudding basin and weigh down with a heavy weight.
Chill the summer pudding in the fridge overnight.
To serve, unwrap the clingfilm from the base of the summer pudding. Invert the summer pudding onto a serving plate and remove the remaining cling film. Cut the summer pudding into wedges and serve with cream (if using) and any remaining fruit syrup.