Combine the juniper, cardamom, allspice, cinnamon, parsley and thyme in a clean coffee filter or a piece of cheesecloth. Tie it tight with string.
Chop the apples, celery and shallots. Peel the brown skin of the ginger root off with a spoon and chop finely. Warm oil over low heat in a soup pot. Cook until the apples and celery soften, about 10 minutes. Add chicken stock, cider and the bundle of spices. Cover and bring to a light boil. Lower heat and simmer for about 40 minutes.
Remove cover and toss the spice bundle. Puree using an immersible blender or a traditional blender, working in batches if needed. (If using a traditional blender, remove the round lid handle and cover the hole with a dish towel; this will keep the hot soup from creating a vacuum; it will be impossible to remove the top otherwise.) Finish by pouring the soup through a fine-mesh sieve into a clean bowl. Stir and push on the solids with a spoon to enhance the flavor. Just before serving, reheat gently over low heat, adding salt and pepper as needed.