Double, double toil and trouble

Fire burn, and caldron bubble.
Fillet of a fenny snake,
In the caldron boil and bake;
Eye of newt, and toe of frog,
Wool of bat, and tongue of dog,
Adder's fork, and blind-worm's sting,
Lizard's leg, and owlet's wing,?
For a charm of powerful trouble,
Like a hell-broth boil and bubble.

Actually, it's not what it seems, I am not casting spells contrary to the belief of some people, I am just making blackcurrant and apple jelly.

Lovely job