If you buy a 'cream cake' and the icing is white rather than slightly yellow, chances are it's made from 'non-dairy whipped topping', also known as fake cream. What is it? Cream is a liquid dairy by-product that's high in butterfat. Most cream is made from cow's milk. It's possible to make it from the milk of goats or sheep but this milk is usually reserved for making cheese. In the days before homogenisation, cream was made by leaving milk to stand, undisturbed, in pans. The rich, fatty cream would separate from the milk, rise to the surface and be lifted off in sheets. These days, it's separated from the milk in a sterile environment using centrifugal force. What to look for: it depends on how you're using it. 'Raw' cream that hasn't been pasteurised or homogenised has the best flavour but you are unlikely to taste it unless you visit a dairy farm. In some places, it's illegal to sell raw cream because of the risk of infection from bacteria such as listeria. Cream that's commercially available has - at the very least - been pasteurised: heated to a specific temperature to destroy harmful bacteria. This cream will last in the fridge for about a week and is best appreciated in preparations that don't require heating. More often in Hong Kong, cream has been heated to an ultra-high temperature (labelled UHT), giving it a longer shelf life but destroying most of the taste. This cream can be used in cooked dishes. How is it available? With varying levels of butterfat content and labelled 'cream' (sometimes heavy cream or whipping cream), double cream and clotted cream. It's also sold sweetened, usually in pressurised cans. Don't use this unless a recipe specifically calls for it (and even then, you may want to substitute your own whipped cream). Cream is also made into sour cream and creme fraiche. What else? To whip, cream should be very cold - if it's not, it will curdle - and needs a butterfat content of at least 35 per cent. How to use: cream adds texture, richness and flavour to savoury dishes such as soups and gratins. It is used to fill and decorate layer cakes, drizzled over tarts and whipped and piped onto desserts. It's also used in mousse, ganache and custard.