Clean, wash and cut the rhubarb into pieces of about 2 cm. Wash the orange hot, grate dry and peel and chop the rind with a pestle ripper in thin strips. Peel the orange so that the white skin is completely removed. Remove the fillets between the parting skins. Squeeze juice out of the parting skins. Peel ginger thinly and cut into very fine cubes
Mix rhubarb, sugar, ginger, orange peel and orange juice in a pot and put it in a cool place for about 1 hour (to make juice). Bring to the boil while stirring, then let it boil fizzily for at least 4 minutes. Roughly dice the orange filets, add them with the rum and bring to the boil again. Fill jam while still hot into carefully prepared glasses and close them tightly
Waiting time approx. 1 hour