This is a wonderfully punchy but not over powering marmalade.
I have broken this recipe down into many short steps so that I could include as many photos as possibly - a picture says a thousand words type thing.
The origins of marmalade: The ancient Greeks learned that quinces slowly cooked in honey would set when cooled. The word 'marmalade' first appeared in the English language around 1480. The first shop selling Dundee Marmalade was set up in Dundee, Scotland in 1797. So Seville orange marmalade, similar to what we make today, has been around for over 200 years.
You need to complete the first 4 steps the day before you are gong to cook the marmalade. Cut all the oranges and lemons into half and extract the juice. Putting the pips into a muslin cloth or bag. Put the juice to one side.
Cut the halves of fruit peel into half again and peel off the membrane on the inside of each piece. Putt the membrane in the muslin with the pips and put the muslin to one side
Take each piece of fruit peel and slice it into shreds no more than 2mm wide. If you do not own a gadget that can do this for you I recommend using a good quality ceramic knife, with wooden chopping board.
Pour all the water into the maslin pan and add the shreds. Pour the fruit juice through a sieve into the maslin pan. Put any bits in the sieve into the muslin with the pips and membrane. Attach the muslin to the pan so that the pips and membrane are under water - as much a possible. Put the maslin an somewhere out of the way and leave overnight or at least 12 hours.
The following day bring the liquid up to a boil and then simmer for 2 1/2 - 3 hours, or until the shreds are completely soft and can be squished easily between your fingers. Turn dow the heat to low and remove the bag of pips and put to one side.
Add all the sugar to the mixture and slowly let it dissolve stirring all the time. If you are not sure if the sugar has dissolved keep stirring for another couple of minutes as you do not want the marmalade to crystallise.
Increase the heat and squeeze the bag of pips into the pan to extract all the pectin. The pectin will look like a thick creamy white liquid.
As soon as the mix has reached a fast boil set the timer for 15 minutes. After 15 minutes turn off the heat and test for a set point.
Testing for a set point method 1: Coats the back of a chilled metal spoon.
Testing for a set point method 2: Pour some onto a small chilled plate and leave for approximately 1 minute. Then push your finger through it. It will ripple and rise up against your nail.
If the mix has not reached setting point boil for another five minutes and test again. If it does not seem to want to set then you can pour in the pectin and boil for 3 minutes.
Once setting point has been reached place an onto a suitable trivet and pour into sterilised jars. Put on lids and leave to cool fully before labelling.