Remove the tough outer leaves from the cabbage and set aside 1–2 clean leaves. Cut the cabbage into quarters and finely shred, stopping when you reach the tough core. Discard or compost the core.
Weigh the shredded cabbage in grams and multiply by 0.02 to calculate the salt needed. For example, 900 g cabbage requires 18 g salt. Place the cabbage in a large bowl, sprinkle with the salt, and massage with clean hands for 5–10 minutes, until softened and juicy.
Add the marmalade and ground cloves. If the marmalade contains large pieces of peel, chop them smaller. Mix well.
Add a handful of cabbage to a clean jar and firmly pound it down using the end of a rolling pin or similar tool. Continue adding and pounding cabbage until the jar is filled to about ½ inch below the neck.
Remove the thick center vein from one reserved cabbage leaf and cut each half into smaller pieces. Press a piece over the shredded cabbage, tucking in the edges to create a flat seal and keep the cabbage submerged.
If the cabbage juice doesn't completely cover the cabbage, add enough 2% brine to cover it. To make the brine, dissolve 5 g salt in 1 cup (240 ml) water. Leave about ½ inch headspace at the top of the jar.
Screw the lids on tightly and place the jars somewhere warm and out of direct sunlight. After 1–2 days, fermentation should begin and the jars may hiss and release some liquid. Place them in a bowl or tray to catch any overflow. Once the overflowing stops after a few days, you can remove the tray.