Immerse the raisins in the white grape juice, leaving them to soak for up to 30 minutes. In the meantime...
Set the oven to 360 degrees Fahrenheit.
Sift the two flours together in the bowl.
Add the sugar to the flour mix, along with a pinch of salt.
Quickly, combine the lemon juice and baking soda (to create leavening), and add to the flour/sugar mix.
Scald (not boil) the milk over a low-to-medium flame (see tip 3.) Then add the 7 tablespoons of butter to the heated milk.
Once the butter has melted, pour all of the heated liquid into the bowl.
Knead the concoction briefly by hand; then add the egg, and blend everything well by hand or with a long-handled spoon.
Drain excess liquid from the raisins and add them to the dough.
Use a tablespoon to spoon portions into well-buttered molds of the metal madeleine pans.
Bake for 20 minutes at 360 degrees.
Dust your zalèti with powdered sugar as soon as they’re out of the oven. Or not (see tip 4.)