Prepare beet greens by washing and drying. Chop both leaves and stems into small pieces and transfer to a large bowl.
1 1/2 pounds beet greens
Sprinkle beet greens with salt. Massage thoroughly to release juices.
2 teaspoons sea salt
Add coriander seed.
1 tablespoon coriander seeds
Pack beet greens into a quart-size jar, pressing firmly to remove any pockets of air. Use your hands or a kraut tamper. There should be enough juice to submerge the solids once the jar is full to within an inch of the jar rim.
Place a weight on the solids to hold them below the level of liquid. Screw on a lid (or use a special fermentation lid).
Set jar out at room temperature. Loosen the jar lid daily to release any built up gasses.
The kraut will be ready within 1-2 weeks. Test it after 7 days to see if it has a tangy enough flavor for you. If not, let it sit longer.
Store in the refrigerator for several months.
Notes
Recipe yields 1 quart jar.
It's crucial that the beet leaves remain covered by liquid as it ferments, to avoid mold. Check your ferment daily to make sure all solids are submerged. If any pieces rise above the brine, push them back down and weight them under the brine.