Blood Orange Marmalade with Cointreau

This year, I made marmalade for the first time and it turned out really well. Blood oranges are also currently in season and I bought 3 kg last weekend intending to eat and/or squeeze them. Well, we didn't eat as many as I'd hoped so I decided to turn them into marmalade as well. I researched recipes until my head was spinning then decided to use the same method I'd used for the Seville oranges but reducing the sugar. I was flying by the seats of my pants but the result is very, very tasty even though the marmalade is a little on the runny side and has the consistency of runny honey. Still, it's bursting with flavour though it's not as red as I'd hope because most of the oranges were more orange than red.

1.5 kg blood oranges + the juice of 3 blood oranges
1.5 kg granulated sugar
2 limes
4-5 l of water
75 ml Cointreau (optional)

1. Place a couple of saucers in the freezer. Then, scrub the oranges and limes to remove the wax. Place into a heavy saucepan and simmer for approx. 3 hours until the fruit is really soft. Leave to cool over night.
2. Do not discard the cooking liquor. Half the oranges and limes and scoop out the flesh into a large heavy based saucepan. Bring to the boil and simmer for half an our.
4. Discard the lime skins. Cut the oranges skins in half and with a metal spoon scrape out the pith, the skin should have a polka dot pattern on the inside. Discard the pith and finely slice the skin. Set aside.
5. Next, line a sieve with a muslin cloth and pour the cooked fruit pulp into it. Drain. Use a potato masher squeeze out to ensure none of the juices are lost.
6. Squeeze out the additional 3 oranges. Measure the fresh juice, juice from the cooked oranges and the cooking water. You need about 2.5-2.75 litres. Make up the difference with cold water. Place in a large heavy based pan. This should only be about half full. Add the sugar and orange peel. Heat up until the sugar has been dissolved.
7. Bring to a rolling boil and boil for 15 minutes. Remove from the heat and put a spoonful onto one of the saucers. Leave for 5 minutes. If it's set it'll wrinkle when touch. If not bring to a rolling boil again and boil for another 10 minutes. Repeat this process until the marmalade sets. Leave to cool for a few minutes, then add the cointreau if used. Stir.
8. Ladle directly into hot sterilised jars and screw the tops on immediately. I like to ladle/pour jams and marmalades into to ahalf litre pyrex jug and pour it into the jars. I also turn the upside down to ensure they seal.
9. Leave to cool and label the next day.