Have you eaten raisins before? They look a bit strange, but
they're very tasty!
You can make your own raisins at home!
What you need:
- Fresh red seedless grapes
- Baking tray
- Something to cover the grapes with - you can use kitchen roll,
baking paper or a pillowcase
- Sun
How to:
This experiment needs at least 3 days of sunshine, so check the
weather forecast before you do it!
- Wash and gently dry the grapes.
- Spread the grapes on the baking tray. Make sure the grapes
aren't touching each other.
- Cover the grapes up with kitchen towel or a pillowcase. Make
sure whatever you're covering the grapes with won't blow away. You
might need to weigh it down.
- Take the grapes outside and leave them for at least three days.
The cover should prevent bugs getting to the grapes. If the nights
are damp, take the grapes inside on an evening and put them out
again the next day.
After three days you should be ready to eat raisins! What do you
notice about the raisins? Are they smaller than the grapes? Are
they lighter than the grapes?
If any of your grapes rot or get damp, remove them from the
tray. Dry grapes will shrivel and turn to raisins, they won't
rot.
What's happening?
Drying red grapes in the sunshine turns them into raisins.
The heat from the sun causes the water to evaporate from the
grapes. It also heats up the sugar, causing it to caramelise.
Because the water has evaporated, raisins are smaller and lighter
than grapes. The caramelised sugar makes the raisins taste
sweet.
Do you know how to make sultanas? Try the same experiment with
white grapes!