Boil 4 1/4 cups water (1 liter), then add 1 1/2 cups sweetened condensed milk (about 350 grams) and stir well. Add 2 cups unsweetened whole milk (about 500 ml) and mix thoroughly. Pour the mixture into a rice cooker and let it cool slightly. Finally, add 2 containers of plain yogurt at room temperature and mix well. Cover and let it ferment for 8 hours.

Chop the fruit (peaches, strawberries, kiwi, and scoop out the pulp of the passion fruit). For each type of fruit, add 3 1/2 tablespoons water (about 50 ml) and 1/4 cup sugar (about 50 grams) to a saucepan. Stir and cook until the mixture comes to a boil. You can adjust the amount of sugar to taste.

Slowly pour the fermented yogurt into bottles. Put the fruit sauce into a piping bag and squeeze it into each bottle, rotating the bottle so the sauce spreads evenly. Refrigerate for about 1 hour before serving for best taste.