A simple experiment using raisins and fizzy drink plus a healthy couscous supper.
Fizzy fruit: raisins, fizzy drink (lemonade, tonic water or similar), tall glass
Fruity couscous: raisins, couscous, stock cube, onion, oil/butter, frozen peas, tinned tomatoes, optional mild curry powder
1. Prepare your supper
Chop the onion and fry gently until soft
Add 1 tsp curry powder, if using, fry for a minute more
Add a tin of tomatoes and a few handfuls of raisins
Simmer the sauce whilst you do some science…
2. Do some science
Pour out a glass of fizzy drink
Drop some raisins into the glass
Watch what happens
3. Back to supper
Add a handful of frozen peas to the pan
Boil a kettle and dissolve the stock cube in 350mL hot water
Add 200g couscous to the stock
Cover and leave for five mins
Fluff up the cous cous with a fork and add to the sauce
Serve with a glass of lemonade or G&T for grown-ups!
What’s going on? The science in a sentence…. Bubbles of a gas, called carbon dioxide that makes the drink 'fizzy', cling to the raisins which makes them float to the surface; as the bubbles pop, the raisins sink again.
The Naked Scientists have a nice explanation if you want to know more about the science. A clear fizzy drink works best. You can sultanas or dried cranberries too. The supper serves 4 although if grown ups are eating too, you might want to accompany with some bread or add some tuna.