9 jars including a big jar in the fridge. Gotta love Delia! http://www.deliaonline.com/recipes/traditional-seville-orange-marmalade,1223,RC.html
I used 3lbs of seville oranges (rather than 2 as this is the size bags the oranges came in) and adjusted the weights of all the other ingredients. I used preserving sugar rather than granulated as that's what I had in the cupboard. I also grated all the peel in my food processor rather than sliced by hand. Worked fine, though as we don't like too much peel, I only put half the peel in the pan and the rest in the muslin with the pips etc. I will probably try slicing it next time to see the difference.