26 February 2009

How to make jelly

As well as investigating how things change, we have been learning about different ‘genres’ or types of writing.  For example, how to write instructions.  Like how to make jelly.  Step by step.

This is what we actually did.

  • open a packet of (solid) green jelly
  • put the jelly into a jug
  • boil some water
  • pour that into the jug with the jelly
  • stir until it has dissolved
  • add some cold water so you have 500mls in all
  • pour the (liquid) jelly into two bowls
  • put them into a cold place to set (or turn back into a solid)

I wonder if jelly-making would work using our instructions rather than the ones written on the packet…..Why not come to the classroom and take a look at what we wrote?  Indeed, why not try out our instructions the next time you make jelly?

Anyway, jelly safely made and set (quite perfectly solid yet still satisfyingly wobbly)…..


the next step was to try to answer one of our questions; namely….

  • Can we turn solid jelly back into a liquid again?

This would involve doing two things.  Firstly taking a taste.



And as you enjoy the cool, sweet, lime flavour, think to yourself, ‘is the jelly in my (warm) mouth a solid or a liquid?’  And I think we are all agreed that unless we loved it so much that we just gulped it down in one wobbly spoonful (!) it melted into a warm sweet lime-flavoured liquid.  Mmmmm.

Next step. 

Leave the second bowl of solid jelly in a warm classroom over night – and see what happens.  A quick survey reveals that two children (Shahrbano and Martin) think it will ‘stay solid’; Quentin, Aabis, Owen, Thomas, Tommy, Shani, Dylan, Sharukh and Harrison think ‘it will turn back into a liquid’.  The rest of the class remain unsure.  Which is OK.

Because as we are fond of saying in Class 2i, there is only one way to find out…..

By the following afternoon, Thursday being a decidedly warm day, our solid jelly had turned back into a liquid.


Now; I wonder what would happen if we put it back into a cold place again?  Can you keep on turning jelly from a solid to a liquid and back again for ever?

PS  Remember our Jelly Race?  And how Harry Hot Water had managed to melt a jelly cube in around 4 minutes…..


but that poor old Katie Cold Water didn’t see to have got anywhere?


Well, even after giving her an extra long weekend to work at it, she still hadn’t got anywhere.  It would seem that in order to melt or dissolve a jelly cube, water needs to be hot not cold.

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