Sunday 29 July 2007

Svante Arrhenius (1859-1927)

You think you know someone and then they go and do something that completely surprises you. Of course, I don’t personally know Svante Arrhenius, but I am well aware of his research. He is a Swedish physical chemist who studied electrolyte behaviour (similar to me) and proposed that chemical reactions must overcome an energy threshold (activation energy) before they will proceed, as described by the Arrhenius equation (which I often use in my work). To my amazement, I recently discovered that Arrhenius also predicted global warming. In 1896, he published a paper that demonstrated how changes in carbon dioxide levels could alter the surface temperature of the earth. Drawing upon previous work by Tyndall and Fourier (amongst others), his calculations showed that halving the CO2 levels would result in a temperature drop of 4 to 5 degrees Celsius, while doubling the CO2 would increase the temperature by 5 to 6 degrees Celsius. The time frame for doubling the CO2 was expected to be around 3000 years, while recent estimates suggest it will take approximately a century. Although the calculations were not exactly on the mark, the results are surprising close to current global warming predictions. Arrhenius believed that a rise in temperature would help to prevent another ice age, and even went so far to suggest that it was necessary in order to sustain the rapid growth in population. Overall, he seemed to have a positive view on global warming. If he were alive today, would he feel the same way?

Friday 27 July 2007

Killer Chocolate Mousse

A friend of mine loves chocolate and so when she and her husband came for dinner last weekend, I knew that a dessert with chocolate should be on the menu. After considering a number of options, I decided to prepare the Mint Chocolate Mousse from Nigella's 'Forever Summer' book. In my desperate search for mint flavoured chocolate, I stumbled across New Tree chocolates from Belgium. These milk or dark blocks of chocolate are flavoured with lavender, blackcurrant, ginger, lemon, bitter orange, cinnamon, coffee, lime blossoms, cactus and guarana (but no mint). In particular, the blackcurrant chocolate caught my eye. The idea of a rich, berry flavoured chocolate mousse sounded like a truly exquisite dessert. Rather than overpowering the mousse with the blackcurrants, I combined this chocolate with normal dark cooking chocolate. The resultant berry flavour was subtle, but with a touch of decadence. I think even Nigella would have been impressed. Here is the recipe:

300g chocolate (mint, blackcurrant or whatever you desire)
2 tablespoons soft unsalted butter
6 eggs
2 tablespoons granulated sugar
garnish (mint leaves, fresh blackcurrants, etc)

Break the chocolate into pieces and place in a bowl along with the butter. Heat in the microwave on medium until melted (approximately 3 minutes). Set aside and allow to cool. Separate the eggs and put the yolks and sugar into one bowl. In another bowl, whisk the egg whites until it resembles stiff snow (but not dry) and set aside. Beat the yolks and sugar together then pour into the chocolate. Fold through until thoroughly combined. Add a quarter of the egg whites and beat vigorously until incorporated. Then gently added the remaining egg whites in small amounts and fold them into the chocolate mixture. Pour into a glass bowl (or 6 individual dishes), cover with plastic wrap and refrigerate for at least 4 hours. Garnish before serving. Serves 6 - and is extremely rich!

Thursday 26 July 2007

Culinary Chemistry

Although I had originally intended to post about science on this blog, it wasn't long before I digressed to posting recipes. I enjoy cooking, especially desserts (as you can see), and when you think about it, there is actually a lot of science in cooking. In salad dressing, oil droplets are dispersed in water to form an emulsion. Marinating meat in an acid (fruit juice, wine or vinegar) breaks down the proteins, making the meat more tender. When boiling an egg, the protein molecules interact with one another (coagulate) to form a gel. Jan Groenewold, a physical chemist and former colleague of mine, has recently released a book with chef, Eke Marien, called 'Cook and Chemist'. They explain the scientific principles behind cooking techniques and how they influence texture and taste. Admittedly, it does take away some of the mysticism of cooking, but definitely intrigues the scientist in me. But can science help me to make the perfect souffle? Well, as they say, the proof of the pudding is in the eating!

Sunday 8 July 2007

Coffee and chocolate self-saucing pudding

Another dinner party at our place meant another opportunity to try a new dessert recipe. This time it was a coffee and chocolate self-saucing pudding from the Donna Hay magazine (Issue 32). The recipe is from the 'Skillet Desserts' article, where each dessert is prepared in a skillet or frying pan. Although I did use a small frying pan, I think it should also be possible to make this pudding in another dish with some minor adjustment to the cooking time. Here is the recipe:

Coffee and Chocolate Self-Saucing Pudding

For the pudding batter, you need:
1/2 cup (125ml) milk
35g unsalted butter, melted
1 egg, lightly beaten
1 teaspoon (5ml) vanilla extract
1/2 cup (150g) plain flour, sifted
1 1/2 teaspoons baking powder, sifted
1 tablespoon instant coffee, sifted
1/4 cup (27.5g) almond meal (ground almonds)
1/4 cup (27.5g) brown sugar

For the sauce, you need:
1/2 cup (55g) brown sugar
1 1/2 tablespoons cocoa powder, sifted
1 cup (250ml) water

For serving, you need:
thick (double) cream or ice cream

Preheat the over to 180 degrees Celsius (355 degrees Fahrenheit). For the pudding batter, place the milk, butter, egg and vanilla in a bowl and whisk to combine. Place the flour, baking powder, coffee, almond meal and sugar in another bowl and mix. Gradually add the milk mixture and whisk well to combine. Set aside.

For the sauce, place the sugar, cocoa powder and water in a 15cm 4 cup (1 litre) capacity non-stick frying pan over medium heat. Stir until the sugar dissolves and bring to the boil. Remove from the heat. Pour the pudding batter to the frying pan containing the sauce. Bake for 25-30 minutes or until firm to touch.

Serve with cream or ice cream. Serves 4 people.

Friday 6 July 2007

So what is it that you do exactly?

When asked the question 'So what do you do for a living?', I sometimes respond by saying 'I'm trying to save the world'. OK, that might be a little bit of an exaggeration, but I do like to think that my work may have an impact on our future lifestyle. Let me explain. My background is in Materials Science and Engineering, and over the last 10 years or so, I have been researching new materials for alternative energy technologies. The aim is to develop efficient batteries, solar cells and fuel cells that will supply us with a clean source of energy and reduce our dependence on fossil fuels (hence, saving the world). More specifically, I study the performance of different electrolyte materials that can be used in these devices. The effectiveness of an electrolyte is dependent on its ability to conduct an electric current, which is directly related to the availability of ionic charges (ions) and how fast they move through the material. The factors that affect the ion mobility include the chemistry and structure of the material and the temperature. By performing a number of experiments, I piece together a picture of how each of these factors affects the overall performance of the electrolyte and what can be done to improve the material. Of course, there is always the desire for faster ion mobility and improved electrolytes, but is there a limit to what can be achieved? Probably, but there are still enough unanswered questions to sustain electrolyte research for at least the time being. So, the end of the world is NOT nigh...well, not yet.