Cut your cabbage in one inch (bite size) pieces and place it in 2 very large bowls.
Add ½ cup sea salt and 1 cup of water to each bowl and toss with your hands to coat.
Let the cabbage sit for one hour, tossing every 20 minutes. You'll start to see the cabbage releasing liquid and shrinking in size - that's exactly what we want!
While the cabbage is sitting, shred your radish, carrots and apple in a food processor. If you don't have a food processor, you can chop them in small pieces. Set aside.
In a food processor, process the garlic and ginger until smooth.
Fold in your Korean hot chili flakes, red pepper flakes (if using) and fish sauce (if using) and ⅓ cup water. Stir until it becomes a paste. Set aside.
After the cabbage has sat for 1 hour, rinse it very well with cold water and then strain the water. Rinse and strain for a total of 3 times. Rinsing and straining 3 times is important because you want to wash away most of the salt or it will be way too salty!
Place your rinsed cabbage in one of your very large bowls (it should all fit in one bowl now).
Add the radish, carrot, scallions and apple and your hot chili/garlic/ginger paste.
With gloves on your hands (important!), toss everything together making sure that the paste coats all the veggies well.
Add the kimchi to your mason jars packing it in tightly. Make sure to leave at least 2 inches of headroom (the kimchi will expand as it ferments). Close the lids to your jars. This recipe usually makes about 8-10 pint size jars.
Close the lids on your jars and let them sit for 3-5 days.
You must "burp" the jars once a day during these 3-5 days. You do that by quickly opening the jar and then closing it. You'll hear gas releasing - just like what it sounds like when you open a soda. That is normal and a good sign! You should see small bubbles in your jar, too. And if you hold the opened jar to your ears, you'll also hear it fizzing. That's like music to a fermenters ears :)
After 3 days, give your kimchi a taste. If it tastes tangy and "fizzy", that means your kimchi is finished and you can move your jars to the fridge. They will last about a year in the fridge. If you don't taste that tanginess, let your kimchi sit for a few more days.
You may want to put the jars on a tray while they are fermenting. If you didn't leave enough headroom, your kimchi liquid could spill out of the jars, leaving you with a big mess - a tray helps catch that liquid :)
Recipe by Primally Inspired at https://www.primallyinspired.com/how-to-make-kimchi/