I am bad at food. I follow the recipe to the letter, but I always end up with bland chicken, rock-hard cookies, and quiche that’s raw inside.
But I still enjoy cooking, because it involves so much of my favourite ingredient: science.
“The process of cooking food is chemistry, period,” former University of Alberta chemistry teacher Roy Jensen says: you’re taking a bunch of molecules and changing them through heat, mechanical stress, and reactions.
If you understand the whys and hows of those reactions, you can perform some fantastic feats with your food.
Jensen cooks for a hobby and has written on the science of cooking.
“The realm of the science of cooking is just starting,” he says.
While cooking dates back to the invention of fire, humanity has only recently developed the technology needed to study the zillions of chemical reactions it involves, he explained. That’s led to the invention of new products (such as more uniform foods and better preservatives) and a new method of cooking: molecular gastronomy.
“Molecular gastronomy is just the application of science to produce certain flavour or textures in food,” Jensen says. He personally uses it to make mango bubble tea.
“It’s oh-so delectable.”
The test kitchen
I asked chefs Peter Keith and Maynard Kolskog to show me how to add some science to my supper.Kolskog teaches molecular gastronomy at the Northern Alberta Institute of Technology, whose test kitchen we have hijacked today. Today, he tells me, we’ll be making smoked sous-vide scallops with foam on edible sand and mango juice balls.
Molecular gastronomy is sort of a catch-phrase for modern cooking techniques and equipment, Kolskog explains. Chefs Ferran Adrià and Heston Blumenthal popularized it in the late 1990s by adapting industrial cooking techniques to restaurant food.
“It takes you out of the realm of simply following a recipe and stewing something in a pot,” Kolskog says.
Cooking is chemistry, and once you’ve mastered the basics, you can do some really impressive stuff with it.
Instead of simply serving passion fruit purée, for example, you can inject it with compressed nitrogen and quick-freeze it in liquid nitrogen so you get a crusty outside, creamy inside, and the ability to breathe “smoke” – Kolskog calls it a passion fruit nitro dragon. You can also create mandarin oranges that are in fact orange gels filled with chicken liver parfait – a specialty of Blumenthal’s.
About five years ago, you’d see a lot of fancy restaurants use molecular gastronomy to make all sorts of weird and wacky dishes more or less to show that they could, says Keith, a Paul Kane alumnus with an interest in this type of cooking. Now that the novelty has worn off, it has become more of a tool than a trend, used only in specific circumstances.
What is cooking
One of the more common techniques used today is sous-vide cooking. To demonstrate, Kolskog takes his scallops and some olive oil, vacuum packs them, and plops them in a bucket of water. He then turns on the immersion circulator (a heater/water pump) and sets it to 60 C.Sous vide is French for “under vacuum,” says Keith, who uses sous-vide cooking to make sausages for his company Meuwly’s Meats. Immersion circulators let chefs evenly heat food and hold them at specific temperatures for hours on end – something you can’t do with ovens or frying pans.
“By cooking in the vacuum bag, nothing’s getting in or out,” he explains. That keeps bacteria out, letting you cook meats for days without fear of contamination, and keeps tasty flavour molecules in.
Most food contains protein molecules arranged in very specific shapes, Jensen says. Add heat (kinetic energy) to those molecules, and they jiggle to pieces and reform into random shapes, destroying bacteria and altering taste and texture. Different amounts of heat result in different reactions and results, which is why rare steak (less heat) tastes different from well done (more).
But heat from a pan or oven has to diffuse to the inside over time, he continues. Heat the outside too fast, and you end up with a roast (or quiche in my case) that’s burnt outside and raw inside. Cook at lower heat for more time, as is the case with sous-vide, and you give the inside time to heat up without incinerating the outside.
Kolskog takes the scallops out of the bag after about 10 minutes then briefly fries each side on a skillet until they’re browned. This is the Maillard reaction, he explains, and the source of meat’s flavour.
You can cook a hot dog by boiling it, but it won’t taste any good, Jensen says. Hit its outsides with more than 120 C heat, however, and you trigger a complex series of reactions between amino acids and sugars that create new flavourful molecules, some of which happen to be brown.
This is one reason why my stir-fried chicken was so bland, I’ve learned. I cooked without much oil or heat, which means this Maillard browning never happened.
Science tricks
For his mango juice balls, Kolskog measures out precise amounts of sodium alginate and calcium chloride powders using a jeweller’s scale, which is accurate to a hundredth of a gram.“I’ll be going much less than a gram on some of these chemicals because they are so powerful,” he explained.
Cooking is chemistry, and chemistry should be precise. But measurements in most recipes aren’t, as everyone has slightly different cups, spoons, and ovens, researchers with Cook’s Illustrated magazine have found.
Their tests found that an oven’s temperature can be up to 50 F different from what you set it at, for example – a huge margin, given that foods can go from done to over-done in as little as 10 degrees. Mine was off by a fair bit, I found when I re-calibrated mine, which could explain why my cookies always seemed over-baked.
Technique also matters. When Cook’s Illustrated researchers had 18 pro chefs measure flour using the same cup, they found that the mass of flour in each scoop varied by 13 per cent. If I weighed ingredients by mass instead, as they recommend, my recipes might get more consistent.
Kolskog adds the alginate to the juice and the chloride to the water. When he pours a bead of juice into the water, the juice forms a sphere instead of dissolving.
Sodium alginate and calcium chloride react to form a transparent gel around the juice called a hydrocolloid, resulting in a juice-filled ball, Keith explains. Using them, you can create spheres of almost any liquid that burst in your mouth.
For the sea foam, Kolskog adds lecithin to a solution of green tea, lemongrass and other substances, and beats vigorously.
Lecithin is a protein found in substances such as eggs. By beating it, you break its protein bonds and cause it to reform into large sheets that, combined with water, create strong, air-trapping bubbles with which you can create meringues, Jensen explains.
Kolskog blends the powder maltodextrin with truffle oil and other ingredients to create edible sand. Keith explains that maltodextrin absorbs oil, allowing you to turn liquids such as olive oil into solid powders.
You too can science food
Kolskog’s gourmet dish is ready within 30 minutes, all using ingredients, techniques, and equipment I could easily use at home. The sand is crunchy, the mango ball tangy, and the scallop smooth and tender.If you want to experiment with molecular gastronomy, Keith recommends looking up the basics online or in books (e.g. The Science of Good Cooking). You can get substances like lecithin from health food stores or online, and buy vacuum packers and sous-vide cookers for less than $200.
Molecular gastronomy isn’t the most practical way to cook. It’s expensive due to the labour involved, and Keith and Kolskog say they don’t do a lot of it.
But it does offer a way to put a new twist on old foods. Keith says you can use lecithin to let someone who is allergic to dairy experience whipped cream, and maltodextrin to create an edible dirt and carrot garden. And some of its techniques, such as liquid nitrogen ice cream and sous-vide cooking, are becoming commonplace in some restaurants.
“Part of food and part of enjoying food is having brand new experiences with it,” Keith says.
Keith says he thinks people can become better cooks if they understand more about the science of cooking.
Will that be the case for me? Let the experiments (dinner) begin!
