Put the whole wheat grains and the millet, oats, rye, and barley in a clean coffee grinder or food processor and process until coarsely ground. Put them in a flameproof casserole, pour in the water, and let them soak overnight.
In the morning, preheat the oven to 300 degrees F. Bring the mixture in the casserole to a boil, add the wheatgerm and bran, as well as the raisins.
Transfer the casserole to the oven and bake for 30 minutes. The texture should be thick, but not sticky. If it is too thick, add a little more hot water. Serve the Kruska with hot or cold milk, or cream, and a little honey, if desired.
This makes a great breakfast for toddlers and the rest of their family members too!