The principles of savoury mousse making are simple but must be followed accurately to ensure a perfect result. Firstly, the prepared meat or fish must be free of all sinew and gristle as these fibres will not break down and will give a grainy result. Salt also plays a big role. It causes the protein in the meat or fish to swell, firming up the flesh and aiding the incorporation of cream.
The temperature of the mixture while it is being worked in the food processor is also crucial. A prolonged mixing process creates heat and if cold cream is added to a tepid mixture, the liquids, fats and solids will separate, giving a grainy texture. A useful hint is to add the cream in a steady stream but fairly quickly otherwise the cream will separate.