Seville orange marmalade

Very surprised to find bitter orange, or Seville orange for sale in the local bio-shop. Bought 2 kg of oranges and made 4.5 litre of marmalade.

 My method of making a really thick marmalade with minimum time in front of the stove:

1. I cut the skin off oranges with a chef knife, trim into roughly 1cm strips and slice thinly. Squeeze juice through a sieve, to collect seeds, into the orange peel.

2. Add 1.5kg of cane sugar to orange peel, mix well and leave to macerate for a day or 2 in the fridge.

3. Put the pulp and seeds into a pan, add 1litre of water, bring to boil, cover with lid and let in cool down.

4. Pass the seeds and pulp thick liquid through a loose sieve, mix residue with a little water and pass again to extract maximum pectin.

5. Mix macerated orange peel and pectin liquid in a vacuum cooking pot, fill to the top with water. Bring to boil, stirring regularly.

6. Place the pot in the vacuum jacket for a day, repeat process if the skin is not totally transparent, adjust sweetness and bottle.