杏吧原创

鈥淵OU are a food scientist. Why can鈥檛 you use science to liven up our
picnics?鈥� asked my wife Wendy, tired of being upstaged by neighbouring
picnickers. It was summer and we were at an open-air concert, the kind where the
ticket reads: 鈥淏ring a picnic and chairs鈥�. This is not as innocent as it sounds.
The picnics in our part of rural Somerset are competitive affairs, with
candelabra and haute cuisine. Wendy, it seems, had had enough of prawn
sandwiches on a tartan rug.

It seemed a fair challenge, so as we listened to the music of Acker Bilk I
began to work on ideas for a scientific picnic that would upstage all the
others. Here follows my vision.

My table centrepiece makes the classiest of candelabra look
pass茅, made as it is from multi-coloured meringues cooked in an oven
full of helium. The meringues float like balloons on the ends of strings above
the table. At dessert-time each guest is offered a water pistol filled with
cream with which to shoot down the meringue of their choice and catch it on
their plate, ready for eating.

The table itself might look like an ordinary portable picnic table, but there
the similarity ends. It has an array of small magnets glued to the underside,
with their north poles pointing upwards. Pairs of plates are glued back-to-back,
concealing an array of magnets in between. Some plates, such as those bearing
meats and pies, have the south poles of their magnets facing down, and they hold
firmly to the table. Other plates, perhaps those bearing salads, have the north
poles of their magnets facing down, and they hover above the table. Stable
magnetic levitation was long thought to be impossible, but my colleague Michael
Berry at the University of Bristol has recently shown that it is possible under
certain conditions if the object is spinning. Slowly rotating, floating plates,
as well as attracting considerable public attention, are ideal for keeping the
food away from ants.

We have champagne, of course, but not in its traditional liquid form. I have
found a way to turn it into champagne jelly. This has the advantage that if your
glass gets knocked over you won鈥檛 lose any. Quaffing spoonfuls of champagne is a
novel experience: as you eat the jelly, the trapped bubbles release their
delicious fizz.

For another fizzy experience, we have crisps lightly sprinkled with citric
acid and sodium bicarbonate. When the crisps are popped into the mouth, these
chemicals dissolve and react to produce a surprising, but not unwelcome,
lemon-flavoured fizz.

Wendy and I learned some of the science for these dishes at a meeting of
chefs and scientists in Erice, Sicily, in May. For example, there are ham
sandwiches flavoured with a mixture of garlic and coffee, and cockles dipped in
white chocolate. Both these combinations were invented by leading chef Heston Blumenthal
(see 鈥淪undae lunch鈥�).
They work by fooling the brain, which
oscillates between the two flavours but cannot mix them. Tobacco-flavoured dark
chocolate, another of Heston鈥檚 creations, provides a similar experience, and is
offered to those who wish to smoke without offending their neighbours.

At Erice, we learned that the degree to which smell affects the perception of
flavour depends on the rate of change of aroma concentration in the nose. So you
can enhance flavour with a quick sniff of an appropriate aroma. This is the
theory behind our picnic tablecloth, which uses a similar material to the Ig
Nobel prizewinning 鈥渟cratch and sniff鈥� suit developed by a Korean businessman
intent on concealing from his wife the aromas of a debauched night out. The suit
releases a powerful scent when scratched. Each square of our check tablecloth
provides a different aroma. We encourage our guests to do a quick 鈥渟cratch and
sniff鈥� of the appropriate square to enhance the flavour of their food.
Sandwiches that have lost their flavour in the rain are restored in this way,
with the guests munching them while sniffing the tablecloth. What will the
neighbours think?

As darkness closes in, we get more adventurous. Out comes food decorated with
the leaves of genetically modified mustard plants that glow a soft green, thanks
to a gene from a phosphorescent jellyfish. The mustard plants were developed by
Rob Ferl at the University of Florida to monitor growing conditions on Mars. As
conditions become harsher, the leaves glow more vigorously. Here on Earth, Wendy
has arranged the leaves to label the different foods on each plate, enabling
guests to identify them in the gathering gloom.

The grand finale, a real eye-catcher, is jelly flamb茅鈥攎y own
invention鈥攆ormed from full-strength vodka or some other strong alcoholic
drink. At home I set these jellies on fire by pouring a little flaming brandy
over them, but here at the picnic I use a propane torch. If left burning too
long, the jelly melts. But I get round this by making it in layers, using a
standard water-based jelly as the second layer from the top to acts as a fire
extinguisher before things get out of hand. As eyes start to pop at neighbouring
tables, I turn to Wendy and say in my best Australian accent: 鈥淧ass the flaming
jelly, dear.鈥�