Peel the potatoes and the onion, cut into cubes, cut the bacon into cubes of the same size.
Sweat everything in a large saucepan with olive oil over moderate heat. Add the caraway seeds, deglaze with white wine and pour on the vegetable stock. Let the soup simmer for 15 minutes. Take a ladle of the bacon and potato mixture out of the soup and keep it as a deposit.
Pour the cream into the soup, season with salt, pepper, marjoram and vinegar and puree everything. Pour the filler back into the soup and reheat. Serve hot!