The science of cooking is much more than liquid nitrogen and Heston Blumenthal-style special effects.
Transforming raw ingredients into tasty meals is one of the easiest and most common ways to understand the ways in which you can work “magic” in the kitchen using basic science.
“When it comes to science in action, the kitchen is the place to be. All cooks are scientists whether they realise it or not,” Leonie Young, owner of The Essential Ingredient Newcastle, told Food & Wine.
“Whether it’s the simple concept of transforming states of matter, like melting butter or reducing a sauce by boiling it down, or more complicated processes such as those used in molecular gastronomy, science is behind everything in the kitchen. It is why cakes rise, why cheese melts, why meat browns, why chips are crisp, meringues are fluffy and why toast burns.”
Changing states of matter is one of the basics. Heat can transform ice from a solid to a liquid and evaporate it to a gas, but it can also take a liquid with a protein base and transform it to a solid.
“Something as simple as making a salad dressing is chemistry. No matter how hard you shake, stir, whisk or blend oil and vinegar, they separate because they are made of different types of molecules. To blend them together you need to add an emulsifier, like egg yolk or a mustard.”
It is also important to understand how proteins behave. Adding fats to carbohydrates, for example, shortens the protein or stops it from bonding.
“Heat and friction will cause proteins to bond to one another which is useful when making things like meatballs or scrambled eggs. But if you want your proteins to be smooth, like in a custard, you minimise handling and keep the heat low,” Ms Young said.
“This is also why you knead bread dough – to form the protein structure to hold the bread up. And you don’t knead delicate pastry because you don’t want to activate those bonds in the protein.”
Molecular gastronomy goes further and uses physics and chemistry to transform food. Blumenthal and Spanish restaurateur Ferran Adria have famously explored some of the trickier realms of kitchen sciences.
“Adria was one of the first to use alginates to create gelled spheres that burst in the mouth,” Ms Young explained.
“Blumenthal recognised the ability of fat to hold flavour and created a dish that had three flavours – basil, olive and onion – with each taste being perceived in sequence. The potential of molecular gastronomy is enormous. It is revolutionising traditional cooking and transforming dining into a surprising emotional and sensory experience.
“Playing with psychology is also part of the scientific fun of this style of cooking. When presented with a bowl of ice-cream, our brain tells us to expect a sweet treat but instead, it could taste like bacon and eggs, or wasabi and fish.”
If you’re keen on experimenting at home, she said, you need a few pieces of simple equipment and some food additives. Not everyone has a liquid nitrogen tank in their kitchen.
“Spherification, foams and gels are an easy way to explore this fun scientific approach to cooking,” she said.
“A really enjoyable science experiment is the 30-second microwave sponge [see below]. It is quick, reliable and easy to master.
“It only contains one integral piece of equipment, a siphon. That’s the kind of of dispenser that uses a gas bulb to aerate the mixture inside as it comes out, and is most typically used to whip cream. We recommend the use of an ISI Cream Whip.
“One tip when using a siphon is to always make sure it has been totally discharged prior to opening the lid. Everyone makes this mistake once but after four hours cleaning mess from the ceiling you never do it again.”
Melbourne Food Depot (MFD) recipe for 30 second sponge (from Leonie Young)
2 whole eggs
sugar, salt and pepper to taste
You will also need a flavour component
For a savoury sponge try: 20g MFD tomato powder or 20g MFD Pineapple Powder and 10g MFD Blue Cheese Powder
For a sweet sponge try: 20g MFD Beetroot Powder or 20g Standard Dutch Cocoa Powder
1. Mix egg, flour and your choice of one of the flavour components and adjust the seasoning.
2. Blend the mixture into a smooth paste, make sure no visible lumps: these will block the siphon outlet.
3. Pour the mixture in a iSi whip and charge it with two cream chargers. Shake hard for a solid 2 minutes. This allows the gas to penetrate the mixture.
4. Take a paper disposable coffee cup and slit the bottom in 3 places the size of a paring knife then spray or rub inside with a light coating of oil.
5. Squirt mixture from the siphon halfway up the cup and blast it in the microwave for 40 to 60 seconds. Some people place the cup upside down in the microwave but we have always done it the normal way. Good chance for some home experimentation!
6. Remove from microwave and use a sharp knife to release sponge from the cup and serve immediately.