Marmalade

Marmalade is made with Seville oranges, a particularly bitter orange with a very short harvesting period. It is possible to make marmalade with other citrus fruit, although ordinary oranges may be too sweet. If you can't get Seville oranges, then I suggest pink grapefruit instead!

Ingredients
Seville oranges, or pink grapefruit
water
sugar

Equipment

saucepan
wooden spoon
sieve
plate
sugar thermometer (optional)
three jam jars with lids

preparation time:
prepare fruit an hour to cook fruit
heat juice, peel and sugar until it jells (220°F / 104°C')

Cooking process

Citrus fruits do not necesarily conform to neat weights! But use roughly the same weight/volume of water to fruit, and 50% more sugar.
Cut the fruit in half, and scrape out the pulp and pips. Put all this in a saucepan (including the pips!) Cut the peel into four more pieces each and add to the saucepan. Add the water. Cook for an hour.
You need to sterilise the jam jar. Wash it in fairly hot water, then fill them with hot (but not boiling) water. Glass will break if you suddenly put too hot water (or jam) in it, but the warm water helps to raise its temperature which makes it safer. Make sure the lid is immersed in hot water as well.
The next two stages are easier if you let everything cool down a little!
Fish out the peel from the saucepan, and cut into chunks suitable for the marmalade.
Sieve out the juice. If you have a muslin cloth, you could use that instead. Squeze as much juice out as possible. Return the juice to the saucepan. (The contents of the seive get thrown away. It should be mostly pips.)
Add the sugar and the cut up peel to the saucepan. Heat until the gelling point is reached. This is higher than the boiling point of water, so first you need to heat it until you see no more steam (which takes some time). Then try dribbling a bit of the jelly onto a cold plate. Tilt the plate, or run your finger through it (careful - it might still be hot!) If wrinkles form, then it is gelling. (If you have a sugar thermometer, then the gelling point is 220°F / 104°C).
Empty the jam jars of hot water and carefully pour the marmalade into the jam jars. Since the jam jar will be hot from the water, it shouldn't mind the hot marmalade. The marmalade will be hotter than boiling water, and will stick to you if you're silly enough to pour it on yourself, so be careful! I tend to do all this in the sink, so if it slops over the edge of the jar, it can easily be washed away. Now screw on the tops (remember that everything will be quite hot!).

Other ideas

Some people put circles of grease proof paper on top of the marmalade. This is to stop mould. I think it's a good idea!
You need to work out how many Seville oranges to buy. It is slightly complicated by the fact that in UK, you buy in metric (kilograms) while jam jars are Imperial (pound). I wanted to make 3-4 jars of marmalade, but found the resulting sum a bit tricky. You do NOT want to buy 3-4 pounds of Seville oranges, as there is the sugar to consider. So a kilo of Sevilles + 1.5 kilos of sugar = 2.5 kilos of marmalade, which is 5.5 pounds of marmalade, which is too much. I worked out (plus getting someone to check my working) that I needed to buy half to three quarters kilo of Sevilles, and I ended up buying four, which weighed two thirds of a kilo. It made 4.5 pots (I don't think they are pound jars!)
Update 2025 - I think it's about one Seville orange per pound jamjar. That was about a pound, so a pint of water and one and a half pounds of sugar. Which made 2 pounds of marmalade. Hm. I presume some of the water got boiled off! Maybe the jars were larger than a pound.