Food critic Jay Rayner was in the city on Monday, bringing his one-man Dining Hell show to the Norwich Playhouse.

In it, he tells of some of his less-than-pleasurable restaurant experiences, with bugbears ranging from waiters having to explain a food 'concept', through ill-thought out fusion food (Italian/Japanese, anyone?), to over-elaborate menu descriptions.

Now, for the food lovers amongst us, it is difficult to feel sympathy for a man whose job is to eat out all the time in some of the UK's top restaurants – at someone else's expense – and then be paid to tell the world what you thought. It sounds like the dream job.

Rayner tells us that his readers love nothing better than a really negative review.

But whilst laying into a terrible restaurant is relatively easy, doing it in an acerbic, witty way, such that people will want to read all 1,100 words, is more difficult. Food writing is more about the writing than the food, something that too many amateur bloggers don't seem to realise.

But if you are going to do a public hatchet-job on a restaurant, you do have to know what you are talking about. The critic should never forget that their review can make or break a restaurant – and, with it, the dreams and livelihoods of the people working there.

So the criticism has to be rooted in a knowledge of food.

This is why I take far more notice of professional critics such as Rayner, Giles Coren and AA Gill than I do of the amateur ramblings found on websites such as Tripadvisor.

During the question and answer session of his show, I asked Rayner whether he had ever considered showing the world how it is done and opening his own restaurant.

After all, if he has such a wide experience of being on the receiving end of how not to do it, surely he must have a good idea of the magic formula which we are all seeking in a restaurant?

Reasonably, he pointed out that he is a writer, not a restaurateur, and that he would stick to what he knows (although, interestingly, his

Kitchen Cabinet colleague Tim Hayward has indeed put his money where his mouth is, and now runs the famous Fitzbillies restaurant in Cambridge, with some success).

The composer Leonard Bernstein said: 'I've been all over the world and I've never seen a statue of a critic.' But that is not to say that they do not play a valuable role in helping us get the best value for our hard-earned cash.

Rayner and his colleagues experience the terrible so we don't have to, and it's entirely right and proper that establishments that charge top dollar for frightful food and surly service should be named and shamed. We should never forget that critics are not there to sell restaurants, but to sell newspapers.

What they write is not just informative, but should be entertaining as well. The laughter amongst the Playhouse audience on Monday evening suggests that more of this entertainment is to be found when the critic has a horrible time than when everything is fine and dandy.

While in the city, Rayner lunched at one of our leading restaurants, and his review will appear in the

Observer in the new year. While we won't know until it's published whether the chef concerned will be getting plaudits or a roasting, we can at least be confident that the review will be fair, witty and written from a position of knowledge – and how many

Tripadvisor reviews can you say that about?