As another academic year draws to a close, many teenagers up and down the land - not to mention their long-suffering parents - will be rejoicing because it means that they no longer have to study the specious and reactionary subject known as 'food technology'. If you haven't had the pleasure of supporting your offspring through this tedious, jargon-ridden discipline, the thinking behind it is that the hands-on cooking that children used to learn in domestic science and home economics is now as outmoded as medieval spit roasting.

So where children were once introduced to the roots of cooking, learning that the 'rubbing in method' was the basis of scones, pastry and crumble, or discovering that a roux was the progenitor of any hot soufflé, white sauce, or macaroni cheese, now food technology treats them as white-coated, net-capped, miniature food industry technologists whose key tool is not a stove, but a computer.

In GCSE food technology, for example, pupils have to 'design and make' a commercial product - anything from an airline vegan meal to a low-calorie dessert - demonstrating that they can use the educationally fashionable, puffed-up and important sounding 'information-communication technology' (ICT), 'computer-aided design' (CAD), 'computer-aided manufacture' (CAM) and 'computer-integrated manufacture' (CIM) to see their idea through to its finished form, all ready for the supermarket shelves. Or, as one exasperated teacher more succinctly put it: 'They spend months in front of a screen producing a 20-page project on designing a low-fat vegetarian muffin. Why can't they just bake the bloody muffins?'

A typical project would consist of drawing up a computerised model flow chart showing the 'hazard analysis and critical control point' system (that's industrial food hygiene to you and me) for a typically British product such as 'saucy chicken animals'. In the context of a cook-chill factory, a diligent student would be expected to show every production stage of this delightful Twizzleresque creation from the preparation of its ingredients through to the filling of heatproof containers, the reheating to a core temperature of 65C, the adding of 'standard components' like previously 'stripped' chicken (whatever gruesome substance that might be), the rapid cooling and blast freezing to -18C, ending with storage and final dispatch in freezer container lorries.

Sensibly, the vocabulary of British food education used to centre on words like sieve, scales, wooden spoon and oven gloves. Now the language that a pupil should master to ensure exam success contains a whole new lexicon of 'key words' such as prototype, mouthfeel, sensory profiling, test kitchen, accelerated freeze drying, conveyor belt, unit cost, designated tolerance, dextrinisation and non-enzymatic browning. By the end of the course, they should be so thoroughly schooled in food manufacturing claptrap that they can answer exam questions such as:

'Complete the five-point specification for a cake- or biscuit-vending machine'

'What are the advantages of continuous flow production?'

'During a production run, why would a food manufacturer use the triangle test for the sensory analysis of custard-cream biscuits ?

Oh, and don't forget the faintly sinister, loaded questions such as 'Explain the advantages of food irradiation'. A prevailing 'Gee whiz, isn't it wonderful?' tone sets any debate. The question becomes not 'Is it always necessary to buy processed food?' but 'Which processed foods should I buy?' Pupils are not encouraged to ask themselves whether a product with a lengthy list of additives is good or bad, or whether most additives are even necessary. Rather, additives are portrayed as a useful technological tool to preserve food and ensure its safety.

Food technology is the perfect educational tool for the food industry because it prepares the younger generation to be compliant consumers of convenience food. If you haven't the skill or knowledge to make a shepherd's pie and some retailer tells you that its ready-meal versions are easily as good as those you would make at home or encounter in a restaurant, then how do you know any better? What a waste of public money it is bombarding pupils with healthy-eating messages if they cannot act on them because they don't know how to cook. And is it any wonder that a government survey has found that consumers in their early twenties were reluctant to use greengrocers, butchers or farmers' markets because - surprise, surprise - 'they express anxiety about entering environments that do not have pre-packed produce available'?

But ultimately, the most disturbing thing about the tenor of food technology is that it encourages the idea that normal food is made in factories by new-product developers wearing hair nets and white coats. As a consequence of its narrow frame of reference where every food is manufactured industrially rather than prepared simply and practically at home, it sends out the message that domestic cooking is no longer relevant.

· Joanna Blythman's Bad Food Britain is published by Fourth Estate at £7.99