5 October 2021
Chocolate isn’t just for eating - it can be used as a scientific tool to study melting points, state changes and measure the speed of light.
Forget about consumption - we all know the joys of rich, creamy chocolate and how delicious it tastes. But as a scientific study, chocolate is a very exciting property as it has a very low melting meaning it’s perfect for a technique called tempering.
Heating and cooling chocolate to give it different characteristics influences how its crystals rearrange their structure. Called polymorphism in the science-y world,this ability to change structure is fascinating, with the fat from cocoa butter able to change structure into six different crystalline forms via melting to alter the appearance or even the sound of the chocolate.
For example, to get that anti-crumble 'snap', tempering is needed, but rapid cooling of molten chocolate provides a smoother texture. Different cooling techniques also affect the glossiness and taste. It can even adjust the properties so that it melts in your mouth but not in your hands.
Chocolate and the speed of light may not sound immediately related, but there is an interesting link. Melting a big bar of chocolate for a short time in a non-rotating microwave enables the measurement of the distance between the melted points, and from this it is possible to work out half the wavelength of the microwaves.
Using this and the frequency of the microwave (for most machines that's 2.45GHz), you can use the equation Speed = Wavelength x Frequency to calculate the speed of the microwaves, which should be the same as (or very close to) the speed of light. Chocolate also has powerful mood-boosting effects in the form of releasing endorphins and dopamine, which the brain creates to help relieve the effects of stress and pain. It also helps promote feelings of calm, whilst the Polyphenols in chocolate are known to slow cell damage and reduce inflammation, as well as other benefits. Dark chocolate has the highest polyphenol content, whereas milk has much lower quantities and is therefore generally less beneficial to health.
