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Chemistry’s love of volatility

By Ann Fenech, on 12 June 2010

Andrea Sella
Interspersing his speech with words including “spectacularly brilliant”, “stunningly beautiful”, “just mesmerising”, Andrea Sella, from UCL Chemistry has just reminded me exactly why I love chemistry. He is clearly enthusiastic about his subject, and that enthusiasm was definitely infectious.

Today I attended a full-house event for Andrea Sella’s event Chemistry: A volatile history with Jim Al-Khalili. The event was based on the recent television series of the same name.

As Sella stated, chemistry always seems to be thought about in connection with pollution, cancer and other negative terms. However, there is so much more to it.

The ancient Greeks believed that the world was made up of 4 elements: water, earth, air and fire. However, as chemists (or alchemists) tried to discover more, they started identifying individual elements, culminating in the development of the periodic table. Quoting Sella, “It’s true that chemistry is about the elements. But it is also about much more than that”.

During the event we saw slow-motion videos from the series, but even more impressively Andrea Sella had numerous demos prepared for us – from burning potassium, to burning diamonds…yes there was a lot of burning!

A truly inspiring event, both for how much information it provided, but even more so for the way it brought that information to your attention in a subtle but exciting manner.

As a chemist I cannot resist ending with this quote, again from Sella:

If it stinks and burns: it’s chemistry;

If it doesn’t work: it’s physics.

A Delicious End to a Delicious Day

By Meghan Harper, on 12 June 2010

I have been looking very forward to the discussion regarding chocolate, and not just for the samples! Food chemistry is so interesting to me because its something that everyone encounters every day, and how different ingredients react at certain temperatures with other ingrediants. Chocolate is a notoriously difficult food to work with, between the tempering, the melting point, and making sure its smooth and creamy, so I was really interested in learning a little bit behind the science of it all.

Scientists Mark Miodownik and UCL Chemist Andrea Sella taught about how the fats in chocolate are the triglycerides, with three carbon atoms and 18 carbon atoms. This means that the saturated nature of this fat has a low melting point. We got to put this into practice when we learned how to properly taste a pieces of chocolate. Are you ready to learn how to property taste?

First, plug your nose. Then put the piece of chocolate in your mouth, and chew it up a bit. When you unplug your nose, inhale through your nose and mouth. This way you can taste all of the flavour notes in the chocolate, and decipher the true flavour. Mmmmmmm. Although for dark chocolates, it is also recommended to let it melt in your mouth. Be patient! When it melts, it releases more tastes and aromas, and in it liquid for it is a richer and fuller taste.

And the ones we tasted last night? To die for! We were really lucky to have Thorntons’ Chocolates and their Master Chocolatier Keith Hurdma provide us with samples of six very fine and really different kinds of chocolates. My favourite was the Crudo chocolate which was an older technique of making chocolate, which was much grittier in texture, as you could feel the large, intact sugar crystals. But we also got to taste samples of cocoa nibs, French Dark, Tonka Milk, Columbia Dark and Madagascan Dark.

And, just in case you need a justification to dive into such an indulgent treat  chocolate affects serotonin levels in the brain, which increase the feelings of happiness. Mark Miodownik also told us about how the physical act of eating chocolate has been linked to the physical feeling of kissing. As part of a balanced diet, in can help you live longer as well. Dark chocolate has almost twice the amount of antioxidants that are present in prunes!

What a sweet way to wrap up the week. Decadant indeed!