Home Forum Chat Forum Which is denser, custard or water?

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• Which is denser, custard or water?
• Depends on the mix of custard but I’d say Custard. Jon Tickle ran across some in Brainiac

Ho hum
Member

Can’t you shake custard violently and it becomes almost solid? I remember seeing that on television once.

nickc
Subscriber

Isn’t it a Non Newtonian liquid? As per Admirable, you can run across it, but stand still you sink.

RealMan
Member

Custard is a non Newtonian liquid (or something like that), so the more force you apply to it you more resistance it becomes. Therefore if you jump into a pool of custard you will not sink, but if you step onto it slowly you will. As for densities, I’m not sure.

crikey
Member

Is density not a measure of how many little molecule thingys you can get into a given space? Water molecules might be smaller than custard molecules (and custard will contain water molecules and sugar molecules and custard molecules) so water will be denser.

miketually
Subscriber

It’s definitely more viscous, but that’s not the same as density.

RealMan
Member

Not sure on the logic there crikey. If you really wanted to find out, measure out 500ml of custard and 500ml of water, then weigh them. The heavier one will be denser.

Random bit coming back from physics a level – I think water has a density of 1000kgm^-3

Anyone?

Cougar
Subscriber

A quick Google would suggest that custard has a density of 1.07g/cm^3. Water is 1g/cm^3. So, custard is nominally denser than water, and tastes better in trifle.

wwaswas
Subscriber

is the custard shark infested?

PeteG55
Subscriber

Wasn’t that down to it being a ‘newtonian’ fluid or something rather than its actual density? I’m trying to remember, because all I saw was that brainiac too.

Graham_Clark
Subscriber

Custard (and corn flour, etc.) are all Shear Thickening Fluids… Stir them, hit then, etc and they become thicker to the point, sometimes of being almost solid… Bit like the fancy stuff in those new style pads (D30, etc.)

miketually
Subscriber

Sea water is ~1.2gcm^-3.

I could float custard on sea water and then fresh water on top!

Bez
Subscriber

Is density not a measure of how many little molecule thingys you can get into a given space?

No, it’s not. HTH HAND.

nickc
Subscriber

Bit like the fancy stuff in those new style pads (D30, etc.)

Get yourself a kilo of water and a kilo of custard and see which fits in the smaller space and there’s your answer.

wwaswas
Subscriber

I’ll warrant a kilo of water will be near as dammit 1 litre.

rootes1
Member

tomato ketchup is the opposite of custard…

it is thixotropic… that is its viscosity is inversely proportionate to its rate of shear…

that is why you have to tap the bottle to get it out…

miketually
Subscriber

They make bulletproof vests out of custard.

Cougar
Subscriber

Ketchup isn’t thixotropic. With thixotropic liquids, viscosity changes over time. http://en.wikipedia.org/wiki/Shear_thinning

Semen is, though. That probably explains why an amount of bottle-shaking is required there too.

Bez
Subscriber

I’ll warrant a kilo of water will be near as dammit 1 litre.

If the figures quoted above are correct, though, then unfortunately so will 1kg of custard.

tron
Member

There’s a journal article where they mention the density of custard if you Google – it’s over 1g/cm^3, so custard’s denser than water.

It’s also thicker.

miketually
Subscriber

Which is denser, custard or water?

t_i_m
Member

more force you apply to it you more resistance it becomes

just an inability to change shape/move quickly, this is more visible the harder/faster that you try to move it. Same with Blu-tack: can slowly shape it but hit it with a hammer and it will shatter.

alex222
Member

Blu-tack: can slowly shape it but hit it with a hammer and it will shatter.

I smell BS

jonb
Member

The problem with custard is that it is viscous so perhaps you could make it thick enough that it would be able to trap air if you mixed it (a bit like angel delight) and then reduce the density.

RealMan
Member

Blu-tack: can slowly shape it but hit it with a hammer and it will shatter.

I have blu tack, and a hammer downstairs. I’ll let you know.

bassspine
Member

Silly putty too, you can slowly shape it but hit it with a hammer and it will shatter.

silly putty certainly shatters if you hit it with a hammer.

The only way to tell about the density is to have a bath in it. Eureka!

RealMan
Member

I smell BS

You smell correct. Blu tack does not shatter when hit with a hammer.

kevonakona
Member

Oh and custard is not non-newtonian. The Brianiac used a cornflour mix (In Richard Hammond’s pool). It has to do with particle to liquid ratios. It’s why sand near the water is hard but when the water runs over it you sink.

If you doubt the above about custard get some and stir it quickly, now get some cornflour slowly mix in a little water until you have no lumps now stir it quickly.

alex222
Member

It was among the many things I hit with a hammer when I was a child.

tron
Member

If you doubt the above about custard get some and stir it quickly, now get some cornflour slowly mix in a little water until you have no lumps now stir it quickly.

Custard powder is just cornflour and colouring IIRC.

kevonakona
Member

Ingredients

570ml/1 pint milk
55ml/2fl oz single cream
1 vanilla pod or ½ tsp vanilla extract
4 eggs, yolks only
30g/1oz caster sugar
2 level tsp cornflour

As opposed to the cornflour thing which is just erm……..cornflour. As above it’s a solid to liquid ratio. custard has much less cornflour and so is not non-newtonian.

Bez
Subscriber

Custard powder is just cornflour and colouring IIRC.

And which of those two ingredients tastes of vanilla then? 🙂

CHB
Subscriber

As said above, custard will be denser.
Also don’t confuse density with viscosity.

Its because custard is a solution and as crikey so beautifully put it, with solutions you can “get more molecule thingys in a given space”. Just like sea water, which is heavier due to disolved salt.
Start getting air trapped in the custard though and all bets are off!

rootes1
Member

”Ketchup isn’t thixotropic. With thixotropic liquids, viscosity changes over time. http://en.wikipedia.org/wiki/Shear_thinning&#8221;

Will have to write to heinz to remonstrate for their misinformation!

Cougar
Subscriber

Heinz in “lying in their advertising” shocker. You’ll be telling me next they don’t have 57 varieties.

theotherjonv
Subscriber

ketchup also has a yield point. Get a bottle, turn it upside down and it won’t flow out.

Shake vigorously (shear it) and it will get less viscous and flow out. HOWEVER; even if you stop shaking it will continue to flow once started, even once the shear is removed.

djglover
Member

I work with Jon Tickle

Fact

Spongebob
Member

I’m hungry now! 😕

*reaches for the Bird’s custard powder. MMMMM 😆

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