Kitchen food science: the weird and the wonderful

The kitchen is a great place to play around with safe — and sometimes delicious — chemical reactions that make things fun, pretty and very tasty.

Here are some of our favourite easy and safe food science experiments to try at home.

FROTHING HONEYCOMB

I have strong memories of making honeycomb in science class at school to see the thermal decomposition of heat reacting with bicarbonate of soda to cause rapid CO2 gas release, trapped by hot syrup to create rapid expansion bubbles.

It still blows my mind, and tastes amazing.

Ingredients:

1½ cups caster sugar

½ cup water

3 tablespoons honey

¼ cup glucose syrup

2 teaspoons bicarbonate of soda (not baking powder)

Method:

Prepare a dependent sided baking tray with baking paper.

In a large saucepan over low heat, combine the sugar, water, honey and glucose syrup. Cook it on low heat, stirring and brushing down the sides of the pan with a pastry brush dipped in water — to stop sugar crystals forming around the edge. Cook for 6 minutes to dissolve the sugar and to start the caramel darkening.

Increase heat and bring the syrup to a gentle boil. Cook it without stirring for another 6-8 minutes. It needs to get nice and dark reach 150°C on a sugar thermometer. If you don't have a sugar thermometer, cook the syrup until is is reduced by ¼ and dark in colour. Remove from heat and set aside to let the bubbles subside a little.

Get your tray ready next to the pot. Add the bicarb to the sugar syrup – it will froth instantly, so quickly stir it all together with a silicone spatula to combine — don't stir too much or you will knock the air out and the honeycomb structure will collapse . Pour the mixture onto on to the lined tray and set it aside to cool completely.

BUTTER MAKING - shake shake shake

This is one of the simplest kitchen experiments, showing off how the physical elements of cream are forced to separate through agitation, causing the fat molecules to stick together and seperate from the liquid whey. Just shake that jar for 5 minutes and watch the magic happen.

Ingredients

Cream

A glass jar with a lid

Method:

Place the cream into a jar that seals tightly and start to shake it vigorously. Keep shaking the liquid as it begins to thicken up up in to 'whipped cream'. Then keep shaking past this stage until the fat starts to separate from the whey.

Keep shaking until the you have fairly separated fats and whey. Drain the whey off and press the fats into a ball of butter, add salt if you like.

CARBONATION

This one is a classic acid-base reaction, releasing CO2 that can be used to add bubbles to liquid. The acid in the lemon reacts with the base bicarb and releases the gas. The reaction can be big or small depending on ratios, so play around with it.

Ingredients:

Juice of 1 large lemon

1 tsp bicarb-soda

Sugar syrup, to taste

Method:

Juice and strain your lemon into a tall glass.

Add 1 tsp of bicarb-soda and watch it fizz! The acid and base react together to create CO2 carbonation.

Add sugar syrup and water to you taste to create a fizzy lemonade.

COLOUR CHANGING NOODLES

Perfect PH play right here — and it's so pretty. The acid is the catalyst to change the PH of the cabbage colour to create a pretty pastel ombré effect.

Ingredients:

1 cup red cabbage leaves, shredded

vermacilli noodles

2 cups water

Juice of 1 lemon

Method:

Shred you cabbbage to help rerelease the colour.

Place the water and cabbage into a pot and bring to the boil. Reduce to a simmer and cook for 10minutes, stirring and pushing on the cabbage to release all the colour into the liquid. Then strain and reserve the liquid and discard the cabbage.

Return the liquid to the heat and add the noodles, making sure they are fully submerged in the purple liquid, then turn off the heat and allow the noodles to cook until they have absorbed the colour of the liquid and are soft — 10 minutes.

Strain the noodles and serve, squeezing fresh lemon over the top to change the PH and cause the noodles to lighten from purple to pink. So pretty!

LAYERED COLOURED LEMONADE

This one shows the tick of density in liquids that have been more or less saturated with sugar.

Start with a simple sugar syrup. Vary up it's saturation by adding lemon in different volumes to each one (and a little food colour) and then layer them into a glass with the densest liquid at the bottom.

Ingredients:

Sugar syrup (1:1 — 1 cup sugar warmed with 1 cup water until the sugar dissolves)

Food colours of choice

Lemon juice

In three different cups make these ratios of liquid:

4 Tbsp sugar syrup + yellow food colour

2 Tbsp sugar syrup + 2 Tbsp lemon juice + red food colour

½ Tbsp sugar syrup + 2 Tbsp water + 1½ Tbsp lemon juice + blue food colour

Method:

Fill a glass with ice (this helps with the layers staying seperate as it slows your pouring down) and pour the yellow dense 'heavy' mixture into the glass.

Pour the red medium density liquid gently on top of that and watch how they sit on me on top of the other.

Finish with the lightest blue liquid and watch it sit on top.

Jane de Graaff is Today's kitchen expert, food writer and recipe developer and content creator for fun family recipes of all kinds.