Cooking Cornflour in Desserts

Marcus issued a clear warning about cornflour in Tom's cheesecake cream: if cornflour is not cooked out properly, it leaves a distinctive chalky, starchy taste that clings to your palate. Cornflour (known as cornstarch in the US) is a common thickener in pastry creams, cheesecake fillings, and custards. When using it, you must bring the mixture to a full boil and hold it there for at least two minutes, stirring constantly, to fully activate the starch and cook away the raw flavour. Tom's cheesecake suffered from this exact problem, with Marcus detecting dryness and Matt describing a claggy, blancmange-like consistency that stuck to his mouth.