Wash the fruit.

Pare the peel from half of the mandarins and shred the peel into very fine strips.

Place the shredded rind into a non-reactive bowl, cover with 500 ml of the water and leave to steep for 24 hours.

Chop the flesh of the peeled mandarins, and the remainder of the unpeeled mandarins as well as the lemons, place the fruit into a large non-reactive bowl, cover with 2.5 litres of water and leave to steep for 24 hours.

The following day, put the fruit and liquid into a large pan and add the remaining 3 litres of water. Bring to the boil and simmer gently for 2 hours, or until the mixture has reduced by half.

Meanwhile, place the shredded rind and liquid into a saucepan, bring to the boil and simmer for one hour. Strain the liquid from the peel, place the peel into a container, cover and refrigerate. Add the liquid to the large pan of simmering fruit.

Remove the large pan from the heat and ladle the mixture into a jelly bag set over a large bowl and leave to drain for 24 hours.

Measure the strained liquid and pour back into the pan. For every 600 ml (1 pint) of liquid, measure 450g of sugar and add to the liquid, add the peel and over a gentle heat, stir until the sugar has dissolved completely.

Increase the heat and bring to the boil. Boil rapidly for 20 minutes and then start testing for setting point.

Once setting point is reached, remove from heat, skim any scum from the top and allow to stand for 10 minutes. Stir gently to distribute the peel evenly.

Pour into jars, seal and lable.

Store in a cool, dark place.