Pick over the raspberries, removing any unripe fruit, and place in a plastic bucket. Pour over it 3 litres (5 pints) of boiling water, then mash the fruit up well with a wooden spoon and add 1 crushed campden tablet. Leave for 2 days then strain off the juice through a muslin, pressing well to get all the fruit juice through. Add the juice of the oranges. Boil up the rest of the water with the sugar and add it to the liquid. Start the yeast and add it when the mixture is cool enough. Leave to ferment in the bucket for 3 days, then move to a fermenting jar with an airlock. Leave it to ferment until all working has stopped, filter and add a crushed campden tablet. Taste it. It may be too dry; if so you can sweeten it with a very small amount of sugar syrup. Bottle in sterilized bottles and store in a cool place.
This is a really special wine with a sharp, distinct flavour, ideal for drinking after a meal. I have found that it is delicious as soon as it has finished working and I have never kept any more than a few months, but as far as I can tell it does not improve with age.