The aim of this investigation is to study the effect of heat on eggs while at the same time producing a palatable dish for all the students. The finished product is assessed by sensory methods to decide which method of cooking produces the most acceptable result.

The investigation enables students to:

• Cook a savoury custard by one of four methods.
• Decide, by observing and tasting each of the finished products which method of cooking is the best for a baked custard
• Relate the results of the investigation to the theory of coagulation.

Practical notes

Ideally, a wok would be used for stir-frying the vegetables but a frying pan is an adequate substitute.

The custards cooked at 160°C, gas mark 3, will take quite a long while to cook - about 40 minutes. They could be cooked at 170°C, gas mark 4 or even 180°C, gas mark 5; in this case the temperature for other custards is increased to 200°C, gas mark 6. The important thing is that two should cook slowly and steadily and two should cook quickly.

The descriptor 'porous' may need explanation. The main feature to look for is tiny holes that appear throughout the custard when it has been cooked too rapidly. This will be associated with loss of water from the coagulated egg mixture 'weeping' or syneresis.

A problem with younger and less adventurous students may be an unwillingness to taste an unfamiliar dish. This savoury custard is in fact similar to the filling for a quiche which is a readily acceptable form of egg custard.

In general, egg dishes which are based on the coagulation property of egg are all 'custards' cooked to a lesser or higher degree. The word 'custard' however has a totally different sensory meaning to the world at large.