The Science In Your Kitchen
By Connor Harbick
Have you ever felt like cooking and baking is scary? Before I really got into cooking, it sure did for me! Cooking felt mysterious and enigmatic, something only for chefs and simply more culinarily inclined people to do, and I’m willing to bet a good many of you at some point felt like this too, or even still do!
This first changed for me at the end of high school, when I was home alone for two weeks, studying for my A-Levels while my family was on holiday, and upon the urging of my mom, decided to cook Shakshuka for myself (A lovely, spiced tomato dish I’d recommend for you to try making!). Of course, I was nervous, worried that I’d make some small mistake while following the recipe and create something inedible. But in my angst, as I often do, I overprepared, watching a dozen videos on Shakshuka. As I did, I became inundated with tidbits and facts about cooking Shakshuka, things like “cook the tomato for 30 minutes to evaporate most of the water and concentrate the sugars and acids” or “sweat out our onions to activate aromatic compounds”. While each fact by itself was helpful, put together I suddenly had a crystal-clear understanding of each Shakshuka recipe I read, and for the first time, I felt confident in what I was cooking! Following these little tips and understanding them, I made what I consider my first real foray into the culinary world:
To me, the best remedy to any cooking anxiety is a strong intuition and understanding of its science. In this blog I hope to dispel some of the dogma for those interested in exploring more of the kitchen at home and explain the science behind a lot of what we do in the kitchen. While this blog might feel like a collection of trivia, I hope that by presenting these ideas to you, you can begin putting yourself in the frame of mind needed to understand a little more about cooking.
How temperature changes your food
The Maillard Reaction
Don’t think: Which of these two chicken breasts looks tastier? Everyone I’ve posed this question to chose the breast on the left, and to varying levels of being able to articulate why, but the common reasoning was “looks more/better cooked”. But let’s try to be a little bit more precise: The difference is in the crust on the meat which comes from a very important concept known as the Maillard reaction. When cooking foods rich in proteins and sugars to temperatures of 150~160°C, these proteins and sugars react together in a cascade of different reactions (the collection of which we call the Maillard reaction), producing a plethora of complex and rich savory flavor compounds that we associate with cooked umami meat. Anytime you hear someone discussing a “good sear” on a meat, really all they mean is achieving the Maillard reaction, and lots of it.
How do we use this information? Most central to achieving the Maillard reaction is this 150~160°C threshold and fighting factors preventing us from reaching this threshold, most commonly: Water.
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Water is present in literally everything we eat, even when not obvious, it is assuredly there, at the molecular level. It is, however, also deeply stubborn, hard capping the temperature of anything in its immediate vicinity to 100°C, as any energy put in must first go towards boiling off the water before the temperature can increase past 100°C. This eats up an enormous amount of time and energy: the energy needed to boil off water at 100°C is 6 times the amount needed to get it from 0°C to 100°C!!! While patiently waiting for the water on the surface of your meat to boil off so we can reach our desired 150~160°C, we risk overcooking the inner section of our meat! A few ways to avoid this:
- Always pat down your meat with a paper towel before searing.
- Avoid overcrowding your pan. Most foods release water as they’re cooked. Leaving your pan uncrowded lets liberated water evaporate/boil off much more easily.
Applying these steps, I was able to get a wonderful sear on these beef cubes (just look at that lovely golden-brown crust!!!). I was then able to use this flavor gold (what it’s seriously called in the culinary world) to create a delicious fragrant beef stock:
This batch of stock has gone on to serve me very well, used in all sorts of dishes: risottos for a family dinner, demi-glace on braised short-ribs for celebrating a birthday, beef-stroganoff pasta for a date.
Just a bit of attention to detail and patience with just one dish, I elevated several more for the people I love.
Slow and Low
Have you ever had really dry chicken breast? Tastes like paper as you pull it apart. Even drenched in a thick sauce, it still can’t be saved. Our first thought on eating any chicken like that is usually that it’s “overcooked”, which, while a fair assessment, requires a little bit more interrogation here! First let’s consult the conventional wisdom on what temperature to cook chicken to:
And most other guidelines you consult by different agencies will usually give this same temperature. They do this because as soon as your chicken reaches this temperature, there will be a log-7 reduction in bacteria, i.e. for every 10,000,000 bacteria, only 1 will remain (shifting the decimal point by 7 places over, hence log-7 reduction). While of course we’d all prefer our chicken bacteria-free, if the center of your chicken is reaching 165°F/74°C, you can be sure the rest of your chicken is reaching much higher temperatures, temperatures of ~170°F, at which the muscle fibers in your chicken begin to contract. As they contract, they squeeze any inter- and intramuscular fat and water out, and never to be reabsorbed again, leaving our chicken fundamentally dry no matter how much water/fat we superficially cover the chicken in. We find ourselves in a dilemma. Is chicken only safe to eat when it’s dry? The answer is of course not, and it comes down to a very important nuance the guidelines skim over: A log-7 reduction in bacteria is as much a function of temperature as it is of time! We can actually achieve this same reduction in bacteria at a lower temperature as long as we maintain this temperature for a longer time:
As we can see, maintaining our chicken at the much more reasonable temperature of ~150°F for less than 5 minutes gets rid of all the scary bacteria we’re usually so worried about, while also not sending the temperature of our meat to the ridiculous highs of ~170°F that would leave it the dry and papery mess we abhor. So why are we given this harsh temperature of 165°F? The pretty straightforward answer is that while the FDA and most regulatory bodies don’t want us to get sick, they also think we’re idiots, and if given all this added nuance, some people might want to cook their chicken for e.g. 2 minutes at 150°F instead of the 3.5 recommended. So, they give the blanket temperature of 165°F because as soon as your chicken reaches there, no matter how long, you can be very confident in already achieving your 7-log reduction! Now, I’d like to think that we homecooks however can exercise a bit of caution and do our best to follow these guidelines well, but of course, how do we? One of your best friends in the kitchen: a temperature probe!
After much trial and error on my part (I count about $50 worth of chicken breasts), here is my personal flow for cooking chicken breast: Put your chicken down on a pan at high (close to your maximum heat setting), and get a quick sear on the pan, but then throw your chicken into the oven at a lower temperature of 130~150°C/250~300°F (These temperatures are much higher than the temperatures we see in the FDA guidelines simply because air, by nature of being a gas and less dense than solids, is a very poor conductor of heat) and occasionally check on the center of your chicken with your temperature probe (don’t leave it to guessing!). Once it hits around ~150°F, let it cook for another 3~5 minutes.
The Mechanics of Taste and Flavor
The importance of salt
Now let’s talk about your real best friend in the kitchen: Salt. At the right concentrations, it reduces bitterness and enhances sweetness, umami, and sourness. Exactly the combination of tweaking the taste knobs on our food we usually want. Without salt, nothing would have any taste! (Hence the addition of salt in dishes that would sometimes initially feel like they don’t need any salt at all, like baked goods!) This was a huge hurdle for me at first! The first 5 or so dishes I made felt like they should have all the right combination of tastes and smells but still tasted a little dead and lacking compared to what I’d get from a restaurant: Pancakes and pastas that were just so puzzlingly bland, despite all the spices added and embellishing I had done. Maybe this has happened to you as well! But what I eventually learned, and my advice to you, is that sometimes all you might need is a kick of salt! Often the only difference between you and a professional chef is their willingness to salt their food.
But for those of us who fear oversalting, we might be tempted to cook a dish from scratch without adding any salt, and at the end add a sprinkle of salt onto each bite. However, if you did so, you’d be left with an inhomogeneous bite filled with an oversalty initial taste, followed by a boring and bland aftertaste. The crucial detail here is that salt takes time to diffuse and penetrate the inner reaches of our food. Salting only at the end of cooking doesn’t always work, especially with thicker chunks of meat or vegetables. Sure, the outside of your vegetables will have their flavor enhanced by the salt, but the inside received no such honor and will lack taste. Add salt early and at different points of your cooking to give it time to diffuse in!
A photo of my first time cooking a steak after learning about the salt, adding lots of salt to my steak and leaving it to dry brine in my fridge the night before cooking. I was terrified that I had oversalted, spent the entire time cooking worrying that my (expensive!) steak would turn out awful, but lo and behold, the steak was perfect; I could taste everything just at the right amount, even the center of the steak, thanks to my salting early and plentifully.
Closing words
I hope you can appreciate the science behind cooking just a little more and are encouraged to understand the reasoning behind steps you take in a recipe. Most importantly, I hope you cook more! Practice and get a good intuition for how all these ideas come together. Experience these ideas and facts for yourself in the kitchen, and get your hands dirty :)
