Kitchen Science: How does an egg cook?

 

This one came from the question "how does an egg cook?" about a boiled egg.  Obviously you can't see inside the shell while it's cooking, so some science was necessary.  I forgot to take pictures of a lot of the process, but it should be fairly self-explanatory (hopefully!!)  

Only takes about half an hour so it's fairly quick too.

Things you need:

11 eggs
A saucepan of water big enough to fit 10 of the eggs in
Labels (we used Post-It notes) with the numbers 0 - 10 written on them
11 pots of some kind to put the eggs in
A cup and a bowl.  The cup needs to fit inside the bowl

What to do:

Boil some water in a large saucepan, once boiling, put 10 of the eggs in.  

Put the labels in the egg box, one in each space, with the unboiled egg in the space with the "0" label.

Take one egg out each minute, putting them in the correct space for how many minutes they have boiled for (boiled for 1 minute goes with label "1" etc.)

Put the cup in the bowl, I've found that even very small children can crack eggs mess-free on the edge of a cup like this.  Sometimes you have to fish shell out, but wherever the egg goes it's contained either in the cup or the bowl.  My 3-year-old has been doing this for about a year and is now brilliant at egg cracking.

Crack each egg in turn, putting the result in one of the pots, and moving the label to the pot so you know which one is which.

Look at the result and talk about it, whatever you notice is great.  We talked about how the eggs cooked from the outside in (that was really clear to see) and about why that might be, and why the egg turns from a liquid into a solid.

She then ate all the eggs that were safely cooked and gave herself stomach ache, but that's another story!

Egg box caterpillar puppet

 

There has been much debate about whether this is a snake or a caterpillar.  It looks segmented like a caterpillar, but has no legs like a snake.  Whichever it is, they're fun to make and fun to play with.

Things you need:

Egg boxes
Blu tack or modelling clay
Something for piercing with (a pencil will do)
Beads or cut up straws
String
Two sticks of some kind (wooden spoons would probably work)
Something for eyes (we used googly eyes and glue, but you could draw them)

What to do:

Cut the egg boxes into individual "cups" - we had 24 eggs worth of egg box, but it can be more or less depending on how long you want your caterpillar to be

Poke hole in the middle of the bottom of each "cup" - put the Blu tack or modelling clay on the table in a lump, put the "cup" right way up on top and stab through the middle of the bottom to make a hole.

Wrap some of the string around the middles of the sticks to hold them together in a cross, then tie the string and cut it off.

The next step is to thread string through the egg box "cups".  This is about 2,000,000% easier if you tightly wrap some tape around the end of the string to make it like the end of a shoelace.

Next you need to get threading all the egg box "cups" on to a long piece of string with your beads or segments of straw in between each one.  We found three beads was about right (approx 1cm)

Tie a bead (or piece of straw) onto the string at each end of the caterpillar to stop the string from slipping through.

Next we gave it eyes.

Tie a length of string (approx 40cm long) near the head end, near the tail end and two more places evenly spaced along the body.

Tie the other end of each string to one end of the sticks you tied in a cross earlier.  As you tilt the cross around the caterpillar will wiggle.  

None of the strings need to be too tight, the caterpillar needs to be able to move freely.

Paper Christmas trees

 

This is one for older kids, it involves spray paint and being careful so I wouldn't try it with anyone less than around 8 or 9, and then only with supervision.

Things you need:

(Forgot to take a picture, sorry!)

A sheet of paper
A dinner plate or something similar to draw round to make a large circle
PVA glue and something to spread it with
Glue gun
String
Green spray paint
Gold rubbing paint


What to do:

Draw round the plate on the paper and cut it out

Fold it into quarters to find the middle and cut down one of the lines

Cover the whole circle in PVA glue

Roll the circle up into a cone, tie a knot in a length of string and poke it through the top of the cone so they can hang to dry

Once dry, use a glue gun to make shapes of Christmas tree decorations

Spray the cones with green spray paint

Use the gold rubbing paint to highlight the raised areas made with the glue gun

Hang wherever you like in your house

Rainsticks

These are great, they make a fun noise and can be as bright and colourful as you like.  This one will need some adult supervision, however, but I did it with my three year old and she managed it really well.  Did take a long time, however, around 45 minutes

Things you need:

A Crisp tube (preferably with a lid)
A kitchen roll middle (must fit easily inside the crisp tube)
6 - 8 wooden kebab skewers or similar
Scissors and tape
Dry rice and a cup
Decorations for the tube (we used stickers)

What to do:

Pierce lots of holes in the tube with the scissors

Push the kebab skewers through the holes and cut off the ends so they are no longer sharp and no more than 1cm is sticking out of each side. 

Wrap the outside in tape to keep the sticks in place and increase the surface area.  Try to make sure that the top and bottom of the tape are stuck to the tube so no rice can get in, and that there are no sticky parts on the outside.

Drop the tube you have just made into the crisp tube.

Measure out approx one cup of rice and pour it into the tube.

Put the lid on (or another circle of plastic cut from somewhere else if you don't have the lid) and tape it down so it doesn't come off.

It will work fine as it is, but we covered ours in paper tape so that it could be decorated with stickers.

All finished!  Now turn it over and listen to the rain.  

A little later we covered it in clear sticky tape so her younger brother didn't pull all the stickers off.  Might be worth considering if you have younger children in the house.