Pack mixture tightly into a glass or ceramic vessel. Ensure that the top surface is even and flat.
If using a small batch fermentation lid, add weight(s) to the jar, then apply fermentation lid.
If using a crock or wide-mouth vessel, add a plastic lid or plate on top of the contents, and a weight to press down and keep contents under the brine. It may not seem very "briny" when you first pack it, but brine will continue to form once the veggies are pressed down. Secure with a cloth and rubber band to keep flies out.
Store in an out-of-the-way spot in your kitchen or house for 5 days. Note: Your house will smell like kimchi.
After 5 days, start to check on the kimchi daily by tasting it. If it still needs more time to develop, let it ferment another day or two. (Fermentation varies by location and season. Nine days is perfect in the drylands Mediterranean coastal climate where I live.)
Once you like the taste and texture, transfer it into mason jars (or remove fermentation lid and replace with the standard mason jar lid) and store in fridge (or swap with your local club members!)
Kimchi will keep in the refrigerator for many months. It will never go "bad" unless it dries out and forms mold. If it is too soft to enjoy raw, consider using old kimchi for stews or soups.