17 Dec Chemistry in the kitchen: science during your Christmas dinner
Did you know that there is some fascinating chemistry applied in the Christmas kitchen? That is why Christmas is the perfect time of the year to show off your chemistry skills to your friends and family. Impress them by serving a scientific Christmas meal! Sure, you could leave the cooking to others and only nerdily comment ‘yummy, you can really taste the Maillard reaction worked out perfectly!’ (Don’t worry – I’ll come back to that Maillard thingy). But why don’t you try and make a laboratory out of your own kitchen? This post provides you with an overview of some awesome cooking techniques that involve chemistry, including a few links to delicious recipes. Be advised: during some of this cooking you might want to wear a lab coat.
The perfect appetiser: non-fish caviar in your favourite flavour!
‘How on earth did you make this?’ your guests will wonder out loud after the flavour of this appetiser literally exploded in their mouths. The principle of spherification is pretty basic and often used in molecular gastronomy. The basis of these eatable spheres can be any liquid, for example fruit juice or pureed veggies. Spherification requires that you mix your favourite liquid with sodium alginate and a salt solution containing calcium ions (for example calcium chloride). The reaction between sodium alginate and salt forms a thin membrane around the liquid flavour. How? The moment you drop the alginate mixture into the calcium solution, the positive calcium ions are incorporated in individual alginate strands, allowing it to polymerize. By using this technique you can make caviar in any flavour you like. From balsamic vinegar pearls to pimp a salad, to very chic carrot-ginger caviar. Molecular gastronomists have even made cocktails in an ice sphere. Although that’s cheating (because no actual spherification is involved), it’s still pretty awesome!
Second course: soufflés of beaten proteins
There is chemistry in every omelette. How it works? Proteins denature when exposed to heat. Less obvious is denaturation as a consequence of beating egg whites with a mixer. Eggs contain both water and proteins. Once proteins have loosened their structure and are exposed to air, hydrophilic amino acids position themselves between water, while hydrophobic amino acids stick out into the air. This process creates a network in which air bubbles are locked up between amino acids. Egg whites beaten to stiff peaks are for example used in soufflés. Soufflés look and taste spectacular, but they are actually quite easy to make!
Main dish: Maillard for the ultimate Christmas flavour
The Maillard reaction is essential for each and every Christmas dinner! The chemical reaction between amino acids and reduced sugars (like glucose and galactose) gives a delicious taste, smell and browning upon heating. It forms the basis of stuffed Christmas turkey, roasted duck breast, bread crusts and even caramelized onions. No way you can ban the Maillard reaction from your Christmas dinner!
Dessert: brandy hot or nitrogen cold?
Burning Christmas Pudding is literally hot! The science behind this amazing looking cake is just a very simple combustion reaction of ethanol. In this reaction, the ethanol from the brandy is turned into water and carbon dioxide (C2H5OH + 3 O2 à 2 CO2 + 3 H2O). But no worries, there will be plenty of alcohol left within the cake to get Christmas-dinner-drunk! The traditional recipe of this dessert is quite complicated, but it certainly is possible to set any cake on fire that you want (all at your own risk).
If you don’t want to risk setting the Christmas tree on fire, you can go in the opposite direction: Ice Fondue. Ice Fondue is easy and extremely cool! The ‘fondue’ is actually frozen nitrogen (-196°), that turns fresh fruits and toppings like chocolate sauce and yogurt into ice cream in an instant. It’s the easiest dish you can imagine (once you have managed to get some nitrogen) and it also looks very scientific!
I wish you a nice Christmas dinner and lots of fun in the kitchen. Please let me know how it worked out and if you cooked or ate other exciting chemistry meals during the Holidays!