Yuzu Marmalade

1. Gather all the ingredients.
2. Wash yuzu thoroughly and pat dry with kitchen cloth. With a knife, remove any black spots on the skin and cut yuzu into quarters.
3. Remove seeds by hand and squeeze out the juice in a sieve (to catch more seeds), set over a measuring cup (or a bowl). Remove the peel by hands (peel is the entire outer covering of the citrus fruit, including the colored, exterior portion as well as the spongy, white pith beneath them.) and separate the seeds and membranes in separate bowls. See the photo below.
4. Wrap the seeds in a cheesecloth and tie with kitchen twine, or pack seeds in mesh tea bags (like this one) and set aside. Why do we keep seeds and use them for cooking? Pectin is released from the cut fruits and seeds during cooking. Simmering the fruit evaporates some of the moisture and concentrates the pectin. Adding sugar and an acid like yuzu juice encourage the pectin to reform as a jelly [Source].
5. Put the membranes in a large pot and fill with a plenty of water. Bring it to a boil and simmer for 10 minutes over medium heat. This precooking process is to soften the membranes and remove bitterness.
6. Remove from heat and drain in a strainer. Let cool and chop the membranes roughly. Put them in a bowl and set aside.
7. While cooking membranes, start removing the pith (the white spongy layer between the fruit and the peel) as it has a very bitter taste. Then cut into thin julienne pieces.
8. Put the julienned peel in a large pot and fill it with plenty of water. Bring to a boil and simmer for 10 minutes over medium heat. Then remove from the heat, drain in a strainer, and set aside. This precooking process is to soften the peel and remove bitterness. If you are not a fan of bitterness taste, you can repeat this process 2 times to further reduce it. I don’t mind, so I did it just once.
9. Now it’s time to weigh and figure out the amount of sugar you’ll need. Calculate the total weight of 3 ingredients: the boiled yuzu peel, boiled membranes, and the reserved juice. My 24 yuzu came out as 1,765 grams.
10. Then measure granulated sugar so that you have half of the combined weight of 3 ingredients, for me the granulated sugar is 883 g.
11. Now combine the boiled yuzu peel and membranes, the reserved juice, and the sugar in a large pot.
12. Add enough water to cover and add the bags of seeds in the pot.
13. Bring it to a boil and simmer gently over medium heat for 30-40 minutes, stirring to dissolve the sugar, and skin any foam on top.
14. When the marmalade is reduced and becomes slightly thick, scoop a tablespoon of marmalade onto a cold plate and let it cool to check the thickness. Marmalade will continue to get thicker as it cools more, so don’t wait till it gets too thick. Remove from the heat and discard the bags of seeds.
15. When the marmalade is almost done cooking, it’s time to prepare the jars. Wash the jars, lids, and bands thoroughly in hot soapy water and rinse. Alternatively, you can also use a dishwasher. I used the water bath canning method (click here to read and click here to watch a video) to preserve this yuzu marmalade. Place your empty jars in a large pot, right side up, and completely cover in hot but not boiling water for at least 10 minutes.
16. Remove jars and lids from hot water. While the jars are still hot, fill them with warm marmalade. Wipe the rims carefully. Each jar should be filled up to a ¼ inch from the top. Make sure to remove any air bubble in the jars.
17. Place the lid onto the rim and seal the jars. Add jars to your canner or large pot with a rack and boil for 10 minutes. Make sure the water covers the jar by at least 1 inch.
18. Remove jars and let them sit for 12 hours. After 12 hours, test the lids to make sure they are completely sealed. If they are not sealed, refrigerate and enjoy soon.

To Store

1. You can keep the sealed jars in a cool place for up to a year.