As a big fan of marmalade I usually eat orange- or grapefruit-based, but the local supermarket had a cheap deal on mandarins, so I thought I would give them a go.
The end result was surprisingly delicious, with a very complex sweetness and just the right tinge of bitterness at the end to balance it all out.
5 pounds (2.2kg) of mandarins
3 pounds (1.25kg) of granulated sugar
40 minutes preparation
90 minutes cooking
10 minutes bottling
Step 1: Wash and Peel the Fruit
Since the peel is going into the finished product, it is probably a good idea to give the outside a good scrub in clean water before starting.
After a number of failed attempts, the fastest way to separate the fruit and the peel was found to be as shown in photographs 2, 3 and 4 above.
Chop each fruit in half around the "equator"
Invert the hemisphere which separates the segments
Ease the segments into one large bowl and then place the rind in another
The lemons don't invert as nicely, so you'll probably have to get in there with a knife to separate their peel and pulp.
Step 2: Remove and Retain Seeds
Mandarins have very few seeds, but will find a few when you slice the fruit in half, and there will be more in the lemons.
Pop these out of the flesh into a bowl and at the end of the preparation, pull all the seeds into a small piece of muslin and boil it in a small amount of water for ten or fifteen minutes while the next stage is ongoing.
Step 3: Chop the Peel
The fastest way to chop all the peel was to stack up half a dozen or so half rinds and then chop the stack into thin strips. Once the strips have been sliced, cut across them a couple of times to leave one inch (2 to 3 cm) lengths.
Once all the rinds have been sliced, dump them into an enormous pot. The pot needs to be much bigger than the volume of marmalade as we are going to simmer it uncovered, and if the liquid is near the top of the pot then there will be a lot of splatter onto the cooker.
Since the lemon peel will likely be in smaller pieces, it needs to be chopped individually, but there are only a couple of lemons while there are about thirty mandarins.
Step 4: Mince Fruit and Add
I crushed the mandarin and lemon segments using a coarse mincer. If you have a juice-maker then you might want to use that.
If you like a clear matrix around the peel in your marmalade, you might wish to strain the liquid through muslin.
However you get it, pour the liquid into the pot with the peel, then add the sugar, and one or two cups of the water in which the pips were boiled.
Step 5: Simmer and Skim and Stir
Once everything is in the pot, bring it to a fairly vigorous boil, but be careful. The sugar/water mixture boils at a much higher temperature than boiling water so splashes will hurt.
As the liquid starts to boil, a fine-grained scum will surface. Skim it off and dump it on a plate for later disposal.
To prevent burning, keep stirring the pot pretty constantly.
Step 6: Preparing the Jars
Turn the oven on to 200F (100C) to warm
Take enough jars for the volume of marmalade you are making, and then add a few spare because things get a bit time-critical later.
Wash the jars and lids thoroughly in hot soapy water and rinse with hot water. Dry the jars and lay them on their sides in the warm over to dry and get hot.
Put the lids in a small pan of water and bring to a very gentle simmer.
Step 7: Fill
Once the marmalade has boiled for about an hour and a half, take a couple of jars out of the oven using tongs, and fill them with the hot marmalade using a ladle or spoon which can pour through the jar neck.
As soon as each jar is filled to the top, take the matching lid from the boiling water using tongs, give it a quick shake to dry and then screw it down tightly, using a tea-towel or oven-gloves to protect your hands.
Once all the jars are filled and sealed, leave them on the worksurface to cool. if there are any spillages on the outside of the jar, leave them until the jar is cool (at least a couple of hours) and then just wipe them off with a damp cloth.
Pack in a cupboard and these jars should last a couple of years, unless you like marmalade, in which case they'll last for a month, tops.
Step 8: Errors and Omissions
1) Do not even think about cutting the pieces of peel individually. I only came up with the "stack hemispheres" method when I realised that it had taken me five minutes to chop two peels.
2) Cutting the fruit from the peel with a knife is another great way to waste an entire day. It is also much messier than the "equator and invert" method of separating the fruit from the peel.
3) There were very few seeds in the fruit I used. The last time I made orange marmalade I had produced a lot of pectin from the seeds in that, so I pulled a block of it from the freezer and added that to what I gleaned from this.
4) Last and most important. Since we are simmering the marmalade without a lid on the pot, the lid associated with the pot had to be placed somewhere. Do _NOT_ place it over a hot ring which you have neglected to turn off. If you do, then the handle will melt and you will burn your hand and get sticky black thermoplastic on your kitchen floor. You will also need to make a new pot lid handle if you are fortunate enough to not break the lid. But at least you'll probably get another Instructable out of it.
Good luck with your marmalade, and please post an "I made it" if you do.