To increase the temperature of the ice cream base (milk, cream, eggs) to around 72 degrees C so as to kill any harmful micro-organisms. Pasteurisation makes food safer to eat and can also decrease the chance of food spoilage or fermentation. Commercial manufacturers of ice cream are required, by law, to pasteurise their products for sale. For those making ice cream at home, it is not essential to pasteurise the custard base. It is a good idea to rapidly cool the ice cream base in an ice bath after heating. This reduces the period where the temperature is optimal for micro-organisms to proliferate.