16 JUNE 2007, Page 43

Cooking in some freshness

Richard Sennett nother box of organically grown fruits and vegetables has arrived on my doorstep, along with an astronomical bill. People who subscribe to this service get produce grown locally and seasonally in Britain, which means the goodies in the box follow Nature's schedule rather than the trade routes passing through Heathrow airport. The bottom-line in this service is 'fresh', a lure which is problematic. What exactly does fresh mean?

To people living in pre-freezer, prerefrigerator times, fresh connotated waste. The logic of pre-industrial farming dictated selling what you could not eat immediately. But this market-logic often broke down; so slow and inefficient were 17thcentury markets, for instance, that apples picked in south Somerset in November went rotten by the time they arrived in London in February. Pre-industrial cooking therefore focused on the techniques of preserving foods, like canning, salting and drying; these techniques still influence our taste buds.

Take salt. Since medieval times, salt has been used as a preservative, either by dry-curing meat or by brining fish. While the human animal needs some salt in food to replace what is lost by bodily perspiration, the use of salt became so heavy-handed that it blurred in time the distinction between fresh and preserved. British and American children — consumers of much too much salt — will say of unsalted vegetables, even those straight out of the farm-box, that they don't taste fresh. Again, hot chillies originated in other cultures as a means of disguising fresh ingredients that had gone off; to a Mexican child, tomatoes served without the capsaicin alkaloid, which makes ground or chopped chillies hot, do not taste fresh.

The refrigerator should have corrected the tastes formed in pre-industrial times, but we haven't used these machines as well as we might. The refrigerated plastic bags of supposedly fresh salad leaves sold in supermarkets, for instance, are often gassed with chlorine, the oxygen then sucked out of the bags into which the leaves are packed; the result is nutrienterosion.

Purist foodies are equally suspicious of frozen raw foods; I am not. Fresh-frozen petits-pois (young, small peas frozen within six hours of being picked) will retain both their nutrients and their natural sugars; whether they taste fresh or not depends on what you do when you unfreeze them. The cooking instructions on the packet tell you to bring the petitspois to a boil. Never follow this instruction! Freezing has altered the inner fabric of each pea, and the pea is now too weak to withstand boiling.

We might think of fresh as straight-outof-the-ground, which is what my virtuous box-co-op charges for, but for many foods this timeframe does not apply. Olive oil has a truly long life as fresh, but it does not possess eternal life. Let's say your label says 'Alpha Zeta Olive Oil Extra Virgin DOP Valpolicella Venezia 2005'. The phrase 'extra virgin' does not refer to the sex-life of the olive. Rather, the 'virgin' bit tells you the oil has been produced simply by crushing the whole olive, pit included, mechanically without any heat applied (thus virgin means coldpressed). The 'extra' bit means there is less than 1 per cent of oleic acid in the oil.

The vintage date, 2005, obliges you to think about how fresh is the olive oil. As a rule, an unopened bottle of olive oil lasts about 18 months, so this particular bottle is now on the cusp of fresh; lay it down in your cellar like a fine wine and in a few years it will stink. Once you open the bottle, it has about six weeks of freshness, though the oil itself will not turn rancid for another year.

The Italian cook rarely has to think about vintage labels, since he or she is likely to use a litre of oil in a matter of weeks; in our cooking, we tend to treat a good oil more sparingly, using it only for special occasions, which puts the olive oil at risk.

Timing applies equally to spices and herbs. British kitchens are littered with bottles of chopped dill-tops and tarragon that have faded in colour and taste. Throw them out, after two months for dill, a month for tarragon.

I've learnt most about freshness by watching Japanese chefs prepare sashimi, which is sliced raw fish on its own, rather than wrapped around rice, as sushi is. In the central fish-market of Tokyo early each morning, suspicion reigns as these professional cooks sniff and poke the fish, subjecting the dealers to policeman-like questioning about where and when the fish were caught.

But this isn't where the story of freshness ends: the chefs believe that slicing the fish in certain ways makes it taste fresh; if the flesh is cut at the wrong angle, noxious oils from the skin will be released; cut the raw fish too thick and all you will experience in chewing is the flesh mass. For the fish chef, fresh is revealed by the work of the human wrist, slicing fish no more than 1 cm wide.

Freshness ultimately has as much to do with how you cook as with Nature. The greatest boon the produce-box has brought to the six young City bankers, the ageing former hippies now producing 'content' for the BBC and the single wealthy antiquesdealer in my food co-op is perhaps, though, quite simple. With all that fresh but fragile food now sitting on the kitchen counter, you cook rather than go out or send out.