In UK we have a small cake called a jaffa cake which has a sponge base with an orange flavoured gelatin disc covered two thirds of base (think flying saucer/UFO shape) and covered with chocolate.
I can temper chocolate and I can cook sponge. I was wondering how they made the clear orange gelatine part. Specifically how can one take orange juice which is opaque and arrive at an orange flavoured clear gelatin?
EDIT: A different way of asking is how come marmalade is clear? I mean I know that one can make a consomme from tomato juice or beef by using egg whites which uses the albumen to filter out pulp but there must be a different technique for orange juice.