 They acquire and mix the ingredients in Owd Grandad's kitchen producing a foul smell in the process.They then leave it to brew in Jack's pigeon coop for over a week, during this time the pigeons decide to roost elsewhere rather than suffer the smell of the concoction.After a week Jack and Owd Grandad return to find their brew (to which much corn and pigeon droppings as well as 3 house bricks thrown in by Jack's grandson had been added) had turned into a disgusting grey slop.