George's Dark Thick Marmalade

Scrub the fruit and cut in half. Squeeze out all the juice, scoop the membranes from the middle of the fruit shells and reserve this pulp with the pips. I've found the easiest way to do this is to turn the half shells inside out and ppel of the membrane by hand working from the centre of the shell outwards. Slice the peel without removing any of the pith, then place it in the pan with the water. It's a good idea to keep the unsliced peel in water while you're preparing it to stop it drying out. Also, it's useful to keep a knife sharpener on hand throughout the process. Tie the pips and pulp in muslin and add to the pan along with the fruit juice. Bring to the boil, then reduce the heat and cover the pan. A heat diffuser on the stove top is useful at this point. Cook gently for up to 2 hours until the peel is tender and can be crushed between finger and thumb. Remove the bag of trimmings and squeeze all the liquid from it. Add the sugar (and pectin if used) and treacle to the preserve and heat, stirring, until it has dissolved completely. Bring the marmalade to a full boil and boil rapidly until setting point is reached. Skim the marmalade, allow it stand briefly and stir it before pouring into pots. The marmalade needs to cool sufficiently before bottling so that the peel does not all float to the top but is evenly distributed.