This is a classic "free form" recipe, in other words, something I just whipped up from stuff I had in the house anyway and without bothering to measure or test. It's absolutely gorgeous.
I've tried to remember general measurements but don't worry, it's pretty forgiving.
Another thing is that it's just a small batch - a couple of jars for us and 1 to give away to a friend. If you make this and want to make more to stock up, just double the recipe.
I should warn you that I like a really strong tart lime flavor. This is it in bags.
13 big juicy limes
5 cups water
1 KG jam sugar - this is a special sugar you can buy in the supermarket that has pectin in it to help fruit jell. It's essential with soft fruits and good with lime because limes have no pits (well, mine didn't) and very thin skins with little pith. It's the pith and pits that release pectin into jams. You must have pectin as that's what makes the marmalade "jell".
You want to use a fairly large/tall saucepan for this because the liquid bubbles up high and FAST when it boils.
1. Slice limes in half, squeeze out all the juices and dump juice into the pan.
2. Slice the leftover peel from about 4 of the limes into very, very thin crosswise strips. Cut the limes halves into quarters to get about the right size for the strips. Six is better but I'm a lazy sod and lime peels are tough and a misery to slice into small thin strips. Dump the strips in the pan with the juice.
3. Now add the 5 cups of water to the pan. I used filtered water because London water is - well it just is.
4. Bring to the boil, then reduce the heat and simmer, uncovered, for 2 hours, until the peel is very soft
5. Add the jam sugar and stir over low heat until all the sugar is dissolved.
6. Turn up the heat and let it boil rapidly for about 15 min. Watch the pan because you will have to adjust the heat occasionally or stir down the boil if it gets too active and starts to rise too high.
7. The mix needs to reach the "setting point". To test for this, put a small glass or china saucer in the fridge when you start cooking. After the mix has boiled for 15 min, move the pan off the heat, dip in a small spoon and drop a teaspoon of the marmalade onto the saucer. Let it cool a few seconds and then blow on it and touch gently with your fingertip. If the surface wrinkles it is ready. If not, boil for a further 5 minutes. When I made the marmalade today it needed 2 extra min cooking for perfection.
8. Take the pan off the heat, skim off any obvious foam -don't fuss. Let it settle for 15 min and then you can ladle it into jars.
9. You can be fancy and use proper canning jars/jam jars. Or you can be like me and save a few small jars and lids, wash them thoroughly, and reuse them for jam. I used 4 small jars for this batch.
10. We'll assume your jars are clean. Just before you fill them, while the marmalade is settling, rinse the jars and lids with very hot tap water, drain and set upside down on a clean dishtowel.
11. Ladle in the hot marmalade leaving about 1/3 inch clear space at the top. Wipe the jar lip with a damp paper towel and put on the lid. Place filled jar back on the dishtowel to cool. You may have enough to partly fill a 5th jar like I did. This is fine. That jar will be ready to use first.
12. Leave the jars to cool and then store all but one (see- that's what the partial one is for!) in a cool dark cupboard.
13. Put up coffee or tea. Make some toast. Butter toast with unsalted butter. Spread some marmalade on the toast.
14. Sit back, sip your coffee/tea. Eat buttered toast with lime marmalade and smirk at the world knowing you have something utterly delicious that you made by yourself.