Wash the yuzu. I used 600 g which is 3 times the amount listed above.
Boil plenty of water in a pot, turn off the heat, and soak the yuzu for 10 minutes (I recommend covering the pot with a lid).
Remove from the water. Cut in half, squeeze the juice out and remove the seeds. Cut the halves into 4 pieces, and thinly slice the remaining pulp and peels.
Add all the juice, pulp, and peel, then the sugar and water to the pot, and turn on the heat to medium. Skim off any scum that floats to the surface.
Simmer over medium-low heat while stirring occasionally. When the peels are transparent, and the mixture just enough that the bottom of the pot shows briefly when you stir the mixture (but is covered by the mixture right away), turn off the heat.
Pour into jars sterilized in boiling water, and keep in the fridge. I used 8 yuzu this time, which were about the same size as the one on the right in the picture, and got 3 jars of jam out of them.
Try making "Yuzu and Cocoa Yogurt" if you like. Recipe ID: 930909
Lots of small yuzu were given to me as a gift this year.
I made this much yuzu jam with them. It was really delicious!
Story Behind this Recipe
I created this recipe because I always get given tons of yuzu every year, and I wanted use them up. They come in handy for flavoring yoghurt and tea. Yuzu jam is great for winter.
Stir very occasionally at first, but once it starts thickening, you should stir more often. When it's finished cooking, it will be still a little bit runny, but when it's cooled down, it will be the perfect thickness. Please be careful not to simmer it for too long.