Tangerine Marmalade

• 2lb/1 kg tangerines
• 1 grapefruit
• 1

Peel the tangerines and cut the peel into fine shreds. Put into a pan with 1 pint/500ml water and simmer for 30 minutes. Peel the grapefruit and lemon and mince the peel. Cut up the tangerines, grapefruit and lemon flesh and put into a pan with the minced peel, water and acid. Simmer for 1½ hours. Strain the tangerine peel and add the liquid to the fruit pulp. Bring to the boil and strain throu