In the end, I made the first batch of marmalade with white sugar, and a generous glug of whisky (about 1/3 cup). I can't believe I never tried this before.
Good? Yeah. "Real good" as they say around here. I just had the craziest mental image of Larry The Cable Guy saying, "Made some real good marmalade-git 'er done!" It probably goes well with crisps. Possibly beer. I followed the basic recipe in the blue book, with a few changes.
Here's What I did:
Finely sliced peels of orange-2 cups (about 8 large oranges)
Chopped oranges-1 quart (about 8)
1 cup thinly sliced lemon, with peel
1 1/2 quarts of water
Bring to a simmer, then simmer 5 minutes. Remove from heat, cover and keep somewhere cool (I kept mine on the counter, but our kitchen is cold when no one is cooking) for 12-18 hours.
Sterilise jars. Set up canner, funnels, rubber spatulas, etc.
Cook peels and pulp rapidly until peel is soft. Make sure you have it the way you like it, as it won't soften any more once you add the sugar. Measure your fruit and liquid. Add sugar in a 1:1 ratio. Stir it in slowly. Keep stirring until it dissolves. Cook *Almost* to the gelling point-marmalade can go super-hard quickly, and unless you enjoy bending all your spoons as you attempt prying it from the jar, keep an eye on it. A jam thermometer helps, but mine has to get to 225 F before it looks even close. Most books say 220, or 218 for jelly-so really, use the spoon test to see if it sheets, or do the cold saucer thing, but don't just rely on a thermometer. You want to catch it just before it breaks in a proper sheet.
Remove from heat, stir in the whisky (it will bubble furiously, so you should stand back as being scalded with hot jam is unpleasant).
Pour into 1/2 pint jars leaving 1/4 inch headspace. Remove bubbles, wipe threads, and seal. Process 10 minutes (adjusting for altitude) and then let cool in the canner 5 minutes before removing. Let stand 12-24 hours before testing seals. It may take a few days to set, though my overflow batch that wouldn't fit in the canner set quickly in the fridge.
Makes about 10 half pints.