I had some left over yuzu, so I removed (a lot) of seeds, sliced it thinly, and mixed it with an equal amount of honey and sugar by weight (mixed with 50% honey, put it in a steralized jar, and then topped with 50% sugar). This’ll turn syrupy and slightly ferment. It’s usually mixed with hot water as a tea, but it can be used for other things.

Edit: After reading what I wrote it seems like it could be confusing. For 200g of yuzu you’d use 100g of honey and 100g of sugar.