The Maillard reaction is responsible for developing colors and flavors. It makes food taste better! Learn the science behind this essential chemical reaction and how it applies to cooking.
Table of Contents
- What is the Maillard reaction?
- Quick history
- Let’s geek out on the science
- Occurs in certain cooking methods
- The role of temperature
- How moisture plays a part
- Ways to remove surface moisture
- Why you don’t want too much acidity
- Maillard vs. caramelization: an identity crisis
- Taste is actually what you smell
- Hungry for more?
The Maillard reaction– you want it to happen when cooking, and here’s why. This highly desired culinary process creates hundreds of new flavor and aroma compounds with the application of heat. The chemical reaction is the visible color change to a stunning golden brown hue on the surface of foods.
The resulting combination of flavor and color change often happens with dry-heat cooking methods under the right temperature, acidity, and moisture conditions. You’ve seen and tasted it before. It’s the perfect crust on a seared, juicy ribeye steak. It’s the crispy amber layer on a pan-seared salmon. It’s the flaky brown crust on a baked apple pie.
What is the Maillard reaction?
The Maillard reaction is a form of non-enzymatic browning that occurs in foods when proteins and/or amino acids chemically react with carbohydrates of reducing sugars. Applying heat during cooking accelerates and continues this intricate process, which elevates the taste, aromas, and appearance of food.
Kitchen experts like Nathan Myhrvold, author of Modernist Cuisine, say the Maillard reaction should be called “the flavor reaction” and not the “browning reaction” due to its essential contribution to flavor and aroma development. It’s the silent star of cooking, acknowledged more for its supporting role.
Quick history
Let’s take a second to thank French chemist Louis-Camille Maillard, who discovered this fascinating reaction around 1910. We can now reap all the benefits from his meticulous investigation and studies.
Food scientists continue to study this topic, and more knowledge of this fundamental principle is being uncovered.
Let’s geek out on the science
The Maillard reaction happens in multiple complex stages. Three things must be available for the response: amino acids, reducing sugars, and water. This is going to sound complicated because it is! But here are some basic things that occur during the process:
- Reducing sugars such as glucose and fructose react with a free amino acid or part of a protein chain.
- Unstable intermediate structures called Amadori compounds are formed that are initially flavorless and colorless.
- New flavor compounds called dicarbonyls are created.
- Hundreds of by-products that will impact flavor, aroma, and color continue to form.
- Brown melanoidin pigment molecules form, responsible for many colors on the surface of foods.
Occurs in certain cooking methods
Most foods naturally contain varying amounts and different types of sugars and proteins. That’s why beef or chicken looks and tastes different than banana bread when cooked. High-heat methods like roasting, baking, pan-frying, deep-frying, grilling, pressure cooking, searing, braising, and stewing benefit from this process.
It’s one of the reasons I always sear meat before adding it to a slow cooker because the moist heat cooking in a Crock-pot never gets above 212ºF (100ºC) for Maillard browning to occur.
The role of temperature
The Maillard process can begin at room temperature. However, turning up the heat nudges it along. Typically, when the food’s surface temperature reaches 300°F (149°C), the process is in full throttle. That means the environment used for the dry-heat cooking method needs to be set at a higher range, 350°F (177ºC) and above.
Caution! Browning reactions are great until food becomes burnt (hello, pyrolysis!). At high temperatures above 355°F (180°C), the surface of food gets blackened and bitter-tasting. It’s a delicate balance that requires attention. So don’t check out on social media for too long, or you’ll be sorry!
How moisture plays a part
A small amount of moisture is needed in the food from a molecular level to aid in the browning process, although too much can impair it. The key is to ensure the food’s surface is dry to prevent steaming and promote the maximum amount of browning for recipes like garlic roasted potatoes.
Some moisture will be released from the food as it cooks. The high heat of the cooking pan and oil will help to evaporate excess water quickly. Reducing the moisture on the surface of a whole roasted chicken will lead to crispy, browned skin faster.
Ways to remove surface moisture
- Dry the surface of the food with paper towels before cooking.
- Air dry meat and vegetables on a tray in the refrigerator overnight.
- Salt foods right before cooking to prevent excess moisture on the surface due to osmosis.
- My reverse sear steak cooks the beef in the oven before pan-searing, drying the surface of the food for quicker browning.
Why you don’t want too much acidity
In science terms, that’s the pH, or how basic (like milk), acidic (mouth-puckering lemon juice), or alkaline (think olives) a portion of food is. The rule is the more acidic the environment, pH 6 and below, the less browning will occur. What can be done? Adding a small amount of an alkaline ingredient, like baking soda, boosts the browning reaction.
This is a clever trick used in Chinese stir-fries to rapidly brown foods since chopped pieces of meat only need a few minutes of wok time. Sprinkling or tossing some baking soda with skin-on poultry also aids in crispiness and color development. I do this for my baked buffalo wings to make them extra crunchy and golden. Give it a try and see the difference!
Maillard vs. caramelization: an identity crisis
Caramelization and Maillard browning are often used synonymously, although they’re very different! They are both non-enzymatic browning reactions, but that’s where the similarities end. Caramelization happens in concentrated sugar environments with a very low amount of moisture. It’s when complex sugars break down into simple sugars, followed by other reactions to create browned colors.
My favorite example is homemade caramel sauce. Depending on the type of sugar, caramelization, on average, begins at 248ºF (120ºC), much lower than the Maillard reaction. Sometimes Maillard browning and caramelization happen succinctly, just at varying levels.
Taste is actually what you smell
When you heat foods, your senses are engaged and lured by many aroma molecules engulfing the air. It’s not a coincidence that when baking a batch of raw cookie dough, 10 minutes later, my son magically appears in the kitchen because of all of the newly emerging sweet and warm smells of chocolate chip cookies that have hit his nose. It’s been researched that about 70% of what you taste is actually what you smell.
Cooked foods trigger this animalistic survival mode in our brain, turning on those saliva glands. Coaxing out the Maillard reaction is a cascading catalyst to what makes people so passionate about food. It’s why I can never turn down a freshly baked flaky croissant, why some people prefer their bagel toasted, the distinctive smell of freshly roasted coffee beans, and why chocolatiers roast cocoa nibs to make dark chocolate.
So spread the word. Now you know the scientific terminology that makes baked goods and meat taste better, the Maillard reaction.
Hungry for more?
Food Science
Smoke Point of Cooking Oils
Food Science
Food Temperature Guide For Cooking
Ingredient Guides
Different Cuts of Beef
Health Notes
Paddy McCarthy says
I don’t understand this sentence in the article:
“Sometimes Maillard browning and caramelization happen succinctly, just at varying levels.”
Did you mean “simultaneously”?
Jessica Gavin says
I believe you are correct! Sorry about the confusion.
Dan says
A quick question for you on the Maillard reaction related to baking Japanese sweet potatoes.
If the Maillard reaction takes place between 135ºF (57ºC) and stops at 170ºF (77ºC).
If the internal temperature of the sweet potatoes rises above 170F and you cool the sweet potatoes down in the oven, for example with the oven off, does the Maillard reaction start again when the temperature hits 170F and continue until it does down to 135F then stops again?
Or does going beyond 170F prevent the process from being restarted?
Jessica Gavin says
Great question! I think that heating the potatoes above the maillard reaction temperatures will halt the reaction. But it also comes down to if there are still starches available to covert to sugar and react with the proteins in the food. Say if the center did not become has hot as the surface when it’s cooled down, there is potential for the reaction to occur and further enhance it’s taste.
Cis Ricchiuto says
It is my understanding that creating this reaction causes the formation of Acrylamides a known carcinogen. ? Can you comment especially with regard to these “air friers” . Thank you for your insights!
Keith says
Thanks for this excellent article.
Jessica Gavin says
You’re welcome, Keith!
Okebaram Ekwuribe says
Great article! I have a tone of questions and if you can answer any that would be splendid. How do fat and oil affect the flavoring process during browning? For example, I have seen people sprinkle oil on meat as they grill it, and at other times it seems the fat from the meat is creating flavors as well. Or could it be inhibiting flavors?
Also when you fry something in oil, it tastes different. Not that it tastes better than grilled, it doesn’t. But it has its own unique flavors that must have been studied too. What reactions are going on there and how do you compare or contrast that, or use that to a flavor advantage, when it comes to flavor and deliciousness maximization during browning.
One more… What about smoking? Smoked fish and smoked meat have their own flavor awesomeness and can taste so good. What is happening when food is smoked and what are the conditions for the reaction (just like you explained the conditions for Maillard browning)? If I could add a PS, it would be asking for cooking tips to maximize browning all through food but at the perfect balance without burning it or undercooking the core, especially meats.
Angshuman Das says
Hi Jessica:
Since you are a food science geek, I have got a question — about the right temperature for the puris (Indian deep-fried savory pastry) to puff up. I know from my mother that the oil has to be hot enough but not too hot — if temperature is lower, the puris don’t puff up and absorb too much oi; on the other hand, too hot will brown or burn before puffing, which involves pressing the pastry into the oil briefly to submerge it.
Looking forward to your answer. Thanks.
Jessica Gavin says
Your mom is extremely wise! The optimal temperature for deep frying is between 325 to 375°F (163 to 191°C). Above 400°F (205°C) and it will brown too quickly and the inside will be raw. I’ve read that you can test the puri by adding a small piece into the oil and if it floats up immediately, it’s the right temperature. I would check with a thermometer in between batches. Let me know how it goes!
ziva says
Thanks for this great post. Did you try baking soda on puff pastry as egg wash substitute? I want to get the brownish effect. Thanks!
Jessica Gavin says
I have not tried baking soda on puff pastry. I have used milk to help with browning if you don’t want to use egg wash. However, it’s not as shiny.
Paul Burke says
Dear Jessica
Having retired, I have only recently become interested in cooking. As a retired industrial chemist I was frustrated that when cooking, which after all is simply a chemical experiment, I could not get reproducible results – fantastic rice pudding one time and a stodgy disaster next.
It was a delight to hit your website – at last a key to my frustration. You can’t believe how many thermometers and timers I now possess.
I looked up the Maillard reaction and can understand the science behind your recommendations. I was vaguely aware that cooking could produce the carcinogen, acrylamide, which results from the reaction of an amino-acid, asparagine, with (free mono-sugars) glucose and fructose at high temperatures. The chances of developing cancer are extremely low, but I think it worth mentioning that storing potatoes in the fridge (which I do to prevent seeding) is not a good idea as it produces extra free sugars and hence more acrylamide. From now on I will store at room temperature.
Please keep the science rolling for this avid pupil!
Mahlon Bouldin says
Hey there. I discovered your site this past weekend while looking for recipes for chicken thighs. I haven’t cooked them yet because I’ve been poring over your pages and loving it all. I appreciate the science angle and also how you dispense it layman’s terms, getting us the information we need to jolt our imagination into further research.
Plus, your recipes look fantastic (videos are perfect inspirations points) and I followed the one for easy fried rice tonight. Having a sister-in-law from China really made me pay attention. It was delish.
Please keep doing your thang. You’ve got a good vibe going on here. Your layout and content on the website is perfectly balanced.
Thank you!!
Jessica Gavin says
Thank you, Mahlon! Your feedback really made my day. I’m so happy to hear that my articles are helping you on your culinary journey.
Patrick says
I just stumbled across this great in-depth info on the science of the magic that happens to food as we love it. Thank you for sharing. I just fell in love with your page. Thanks again
Jessica Gavin says
You’re welcome, Patrick! Maillard browning is a concept that really changed the way I thought about food and why I love cooking and eating SO much!
Heather says
On this page, you mention adding baking SODA to a recipe to increase browning (for stir-fry cooking, Buffalo wings, etc.). However on your linked Buffalo wings page, you say to use baking POWDER. Which one is it? I read on your soda vs. powder page that baking soda is 4x more powerful than baking powder, but you also only used the word “alkaline” on that page to describe baking soda. So… I’m confused! 🙂
Jessica Gavin says
Hi Heather- Baking soda and baking powder both contain sodium bicarbonate (an alkaline substance), however, baking powder also has a built-in acid to make the bubbling reaction happen more consistently. I like to use baking powder on the wings because I want a bubbly reaction on the skin surface so there is more crispiness. There isn’t anything very acidic in the wing recipe, so choosing baking powder helps the reaction happen. I hope that helps!
Marlus Cajazeira says
What an excelent post!
Thanks to explain this complex theme in a simple way!
I started to know your blog yesterday and I’m really enjoying it.
Congratulations