Both the yoghurt and grandmother's milk sound wonderful.
You live in an interesting part of the world. I am in rural Australia.
How are the pickles and sauerkraut made? Do you make them?
What other fruits are you thinking of fermenting?
For me pure fruit ferments have been least successful. I prefer making dried fruit, and using the dried fruit as a ferment addition. I have done different forms of "Umeboshi" plums and put many different fruits in with other ferments. For example Apple pulp with rice and a littler nutmeg, dried quince in wheat garlic and ginger. Both were delicious. Not to mention using those fruits in pemmican/kimchi or similar.