The joy of lining up the jam jars on the dresser

When Wilson resigned, the editor suggested I ask the makers of HP Sauce if sales would plummet

Vague suspicions I've had for some time were officially confirmed this morning by a spokesman from the Institute of Grocery Distribution, an organisation as crucial to the quality of our lives, though possibly not as romantic, as the Herring Board and White Fish Authority. Dr Richard Hutchins, the institute's business director, announced that in the last 10 years there has been a 30 per cent decline in jam consumption which, if the trend continues, could mean that by the year 2032 we will be buying a staggering 70 per cent less jam than we were in 1992, when my youngest son was three.

I mention this detail only to demonstrate that if Dr Hutchins had asked me 10 years ago if I thought people were eating less jam, I could have put him straight immediately. "If you can spare the time to come to my son's birthday tea party this afternoon, Dr Hutchins," I would have said, "you may judge for yourself whether the eating habits of the younger generation vis à vis jam are undergoing what I can only describe as a seismic shift."

Dr Hutchins at the other end of the telephone gasps, stifles an oath and then, composing himself, replies: "Thank you for your invitation, which I know my colleagues at the institute will urge me to accept for, as you must surely be aware, any information regarding the consumption of teatime preserves in the United Kingdom is of vital importance to our future business strategy."

"I do not doubt it Dr Hutchins – may I call you Richard?– and I very much look forward to seeing you at around 3.30," I say, and lay another Mr Happy paper plate on the festive table.

Incidentally if you're wondering at the old-fashioned formality of this exchange, let me assure you that this is how people who work in institutes speak. When Harold Wilson resigned, the editor of the gossip column I was working for suggested I telephone the company that makes HP sauce to find out if they thought sales would plummet now the country's most famous consumer of their product was no longer at No 10. I was eventually put through to the PR who advised me coldly that they were not anticipating any change in sales patterns. "The brown sauce market is not susceptible to political fluctuation," he said.

I love jam. As a child, blackcurrant jam was my favourite, and as a treat my mother would pour the top of the milk bottle into the empty jam jar, swoosh it around and then give it to me as a milkshake. I used to make jam, gallons of it. There was a pick-your-own-strawberry farm near our house, and towards the end of the season, when the notice outside said "jam strawberries 10p a pound", we'd all trek down the lane, the children on bikes, the baby in the pram, and spend the whole afternoon eating and picking huge juicy strawberries too ripe to sell as pudding fruit but perfect for jam. The satisfaction of lining up 40 bottles of neatly labelled home-made jam on top of the kitchen dresser cannot be exaggerated.

When my older daughters were small, they made jam tarts and Victoria sponges layered with jam, and were happy to have jam sandwiches at picnics. It was my youngest daughter who bucked the trend. For her birthday tea she didn't want jelly and jam tarts. She wanted crisps and Twiglets and cocktail sausages and, if I insisted on sandwiches, they too had to be savoury. "Would you like an egg sandwich, Lucinda?" I asked a pouting five-year-old in purple satin hotpants. "Are they free range?" she said.

I stopped making jam long ago, but I do still make marmalade. There are 17 pots of home-made Seville orange marmalade on the dresser, some dated 1999 because, as Dr Hutchins said, eating habits have changed. My sons don't want toast and marmalade for breakfast, they want pasta with pesto sauce and, if there's no time to cook pasta, they'll spread the pesto on bread and race for the bus. They still have a sweet tooth, intermittently grazing on huge bowls of ghastly cereal containing caramelised fruit, toffee-coated nuts and even, God help us, chocolate chips.

As for jam jars – good-old fashioned, straight-sided clear glass jam jars, none of your fancy crinkled coloured rubbish – whatever happened to them? I want two dozen to fill with roses from the garden to put on the tables at my daughter's wedding next month and all I've got are empty Marmite pots. Oh well, this could be the start of a new bridal trend.