Use a food processor, OR purée soaked nuts in a high-powered blender, with filtered water and oil until mostly smooth (about 1 minute [or longer for blender]). Add sauerkraut juice. Pulse again until just combined (about 10 seconds). Scrape into a glass or ceramic bowl. Stir in chia seed meal well. (Note: If you use a blender, you'll need to stop and start and use a tamper or wooden spoon to get the purée going. I use a blender personally, but it's a bit more work. See Recipe Notes for process photos.)
Cover loosely with a towel or plate. Place in a very warm location (ideally 95 to 105 degrees Fahrenheit) for 10 hours or overnight. I like to use a warming mat or nest my bowl over my Instant Pot on the Yogurt setting. Fermentation in a cool kitchen will still occur but it will take longer, about 24 hours.
Once nuts and seeds are soured (fermented), preheat the oven to 350 degrees Fahrenheit. Grease just the ends of a loaf pan and line with one strip of parchment paper (which allows you to pull it out easily).
Sift together coconut flour, psyllium, sweetener, baking soda and sea salt. Set aside.
Add eggs to soured nut and seed mixture.
Add flour mixture. Mix with handheld electric beaters until thoroughly combined. With your hands or a rubber spatula, form into loose loaf shape. Place into greased loaf pan. Gently pat and smooth the loaf so it's slightly mounded in the middle.
Bake until a sharp knife inserted into the center comes out clean (about 45 minutes) or it looks done. Loaf will be well browned, more so with some nuts than others.