three fruit marmaladerating:
3lbs fruit (6 oranges, 1 grapefruit, 2 lemons is about right)
2lbs golden granulated sugar
2lbs jam sugar*
1lb dark brown or moscovado sugar
2 pints fresh-pressed English apple juice
1.25 pints water
0.25 pint lemon juice
small knob of butter
(* I like to use a bag of jam sugar to ensure a firm set - you can substitute 2lbs more golden granulated if you prefer.)
Cook whole, scrubbed fruit in apple juice slowly until very soft. I tend to do this an evening ahead and leave the fruit to go cold overnight.
Save the cooking liquid. Cut the fruit in half, scoop out the insides - including most of, but not all, the pith - and put in a pan with the water. Simmer for 15 minutes (go gently, it can catch quite quickly) then sieve the resultant liquid into your preserving pan along with the liquid the fruit was poached in. Add the lemon juice and various sugars, along with the peels, which you have sliced, chopped or shredded to your preferred thickness. Slowly heat the mixture, stirring occasionally, until the sugar has all melted. Bring to a rolling boil, add the butter to help prevent the formation of scum and then boil continuously until
setting point is reached.
Depending on the size of your preserving pan this will take around 40 minutes. (As with all jams you need to keep an eye on it while it's boiling but because this is a very 'liquid' recipe I have found it rises higher in the pan than, say, strawberry jam, so make sure your preserving pan is large enough.) Once setting point has been reached, turn the heat out, skim immediately if necessary and let the marmalade settle for a few minutes before stirring the peels through (this will help keep them suspended in the jars and not float to the surface).
At this point, if liked, you can add up to 4 fl oz of whisky, rum or brandy. Stir well and pot in the usual way.
I have found a small amount of pith left on the peel helps to prevent it from hardening while it boils. The first time I made marmalade I spent ages scraping off every vestige of pith and then had to sieve it all out of the end product and pot up orange three-fruit jelly because the peel was inedibly hard and chewy. Even re-boiling it in water didn't help.
If, when pouring the marmalade you find the peel still floats to the surface, leave it for half an hour or so and stir each pot with a knife until the stuff sits throughout the jar. In this case, leave the jam until stone cold before potting.
It is possible to make this marmalade using all white sugar, but I find a mixture of golden granulated and moscovado gives a dark finish that approximates to Cooper's Oxford.