"Well secret_garden32000, the thickness of your potion depends on a variety of factors. Sometimes the type of cauldron you have affects the viscosity of the brew, though; it's not the largest factor. Usually it is the quality of the ingredients that you use for some ingredients tend to loose their potency after a long time sitting on a shelf so when you go to use it in your brew, it's not working at its full potential. A good book to help with your problem is 1-2-3 Thicken!-A Guide to Potion Coagulation," says Madame Rowena with assurance.