Caramelization vs Maillard: They're Not the Same Thing

Most people use “caramelization” and “browning” as if they mean the same thing. They don’t. And mixing them up can actually make you a worse cook. Once you understand the difference, you’ll have much better control over how your food tastes.

Let’s start with caramelization specifically.

What Caramelization Actually Is

Caramelization is the thermal decomposition of sugar. Chemists call it pyrolysis (from the Greek for “fire” and “loosening”). When you heat sugar past a certain point, the molecules don’t just melt. They break apart and recombine into hundreds of new compounds.

Those compounds are what give caramel its complex flavor. You get buttery notes from diacetyl. Nutty, toasty flavors from furans. Fruity esters. Bitter high-heat compounds that balance the sweetness. Caramel color comes from large polymers called caramelans, caramelens, and caramelins that form as the reaction proceeds.

This is purely about sugar. No proteins involved. That’s the key difference from the Maillard reaction, which requires both amino acids and sugars to produce browning. Caramelization can happen in a completely protein-free environment.

Temperature Thresholds by Sugar Type

Not all sugars caramelize at the same temperature. This matters more than most home cooks realize.

Fructose: around 220°F (104°C)
Glucose: around 230°F (110°C)
Sucrose (table sugar): around 320°F (160°C)
Maltose: around 356°F (180°C)
Lactose: around 392°F (200°C)

This is why honey and agave (which are high in fructose) brown faster than recipes that use plain table sugar. It’s also why onions, which contain glucose and fructose, caramelize at lower temperatures than pure sucrose would.

Sucrose is a disaccharide, meaning it’s one glucose molecule bonded to one fructose molecule. When you heat sucrose, it first hydrolyzes into those two component sugars before the real caramelization kicks in. Acid in the pan speeds up that hydrolysis, which is one reason some recipes add cream of tartar or a squeeze of lemon juice.

Stages of Caramelization

Think of caramelization like a countdown you can’t pause. Each stage produces different flavors, and the window between “perfect” and “burned” is narrow.

Clear melt (320°F): Sucrose melts into a clear liquid. No color, no browning yet. This is where you start a dry caramel.

Light golden (340°F): First color appears. Mild caramel flavor. Good for pralines and light desserts.

Amber (350-360°F): The sweet spot for most caramel sauces. Rich, complex flavor with some bitterness starting to develop.

Deep amber (370-380°F): Intense flavor. Noticeably bitter. Used in savory applications and some candies.

Burned (above 390°F): Acrid, sharp bitterness dominates. The volatile compounds that smell good have mostly cooked off. You can’t come back from this.

A candy thermometer is your best tool here. Color alone is unreliable because lighting conditions and pan color affect your perception.

Dry Caramel vs Wet Caramel

There are two approaches to making caramel, and they behave differently.

Dry caramel: You put sugar directly in a pan with no water. It melts unevenly and requires constant attention, but it moves faster and produces a slightly more complex flavor because you’re concentrating the caramelization process.

Wet caramel: You dissolve sugar in water first (usually a 2:1 sugar-to-water ratio by weight), then cook until the water evaporates and caramelization begins. This is more forgiving for beginners. The water acts as a temperature buffer early in the process.

With wet caramel, don’t stir after the sugar dissolves. Stirring introduces nucleation sites where crystals can form. Swirl the pan gently if you need to distribute heat. Brush down the sides with a wet pastry brush to prevent crystals from forming there and seeding the rest of the batch.

Why You Add Cream and Butter at the End

When caramel reaches the color you want, you add cold cream or butter to stop cooking and create a sauce. Here’s why this works.

The cold liquid rapidly drops the temperature, halting the reaction. But more importantly, the fat molecules from the cream and butter physically coat the sugar polymers. This creates a stable, glossy sauce that won’t re-crystallize at room temperature.

The violent bubbling when you add cold liquid to hot caramel is expected. The water in the cream flashes to steam instantly. Use a tall pot and stand back.

How It Differs From the Maillard Reaction

The Maillard reaction is sometimes called “non-enzymatic browning” and it requires two ingredients: a reducing sugar and an amino acid. When heat brings those together, they react to form a completely different set of flavor compounds called melanoidins.

Maillard browning happens on the surface of meat, bread crusts, roasted coffee, and seared vegetables. It’s responsible for most of what we think of as “savory” or “roasted” flavors.

Caramelization is sugar only. It produces sweetness alongside the complexity, whereas Maillard flavors often trend toward savory.

Both can happen simultaneously in the same pan. When you sauté onions, you’re getting Maillard browning on the proteins in the onion cells and caramelization of the sugars at the same time. This is why caramelized onions are so complex. They’re running two browning reactions at once.

A quick way to tell them apart: if you can get the browning to happen with pure sugar and no protein, it’s caramelization. If protein is required, it’s Maillard.

Why Caramelization Matters for Savory Cooking

Caramelization isn’t just for desserts. Understanding it changes how you approach savory dishes too.

When you cook onions low and slow for 45 minutes, you’re caramelizing their natural sugars while also driving off water. That sweet, jammy depth in French onion soup is mostly caramelization at work.

Roasted carrots, beets, and other root vegetables develop caramel notes as their natural sugars break down. Higher oven temperatures (400°F+) push this further.

Even the browned crust on a crème brûlée is caramelization. You’re applying direct heat to pure sugar with a torch and watching the reaction happen in real time.

Troubleshooting Caramel Problems

Crystallization (grainy caramel): This happens when sucrose molecules reassemble into crystals instead of staying in the amorphous state you want. Prevention: add an interfering agent like corn syrup, invert sugar, or a few drops of lemon juice. These molecules physically block sucrose crystals from forming. Also avoid stirring once the sugar is melted.

Burning on the edges: Your heat is too high or unevenly distributed. Use a heavy-bottomed pan (stainless or copper ideally) and keep the flame centered.

Caramel seizes when you add cream: The liquid was too cold and the temperature drop was too drastic, causing some sugar to re-solidify. Warm your cream slightly before adding. Or keep stirring over low heat and it will usually re-melt.

Too light/too dark: You need a thermometer. Color perception changes under different lights and with different pans.

Deep dive: The chemistry of caramel flavor compounds

Caramelization produces over 100 distinct volatile compounds. Researchers have identified the key players responsible for different notes:

Diacetyl (2,3-butanedione): This is the same compound responsible for buttery flavor in butter and many fermented dairy products. It forms in the early stages of caramelization. Your nose can detect it at extremely low concentrations.

Furans: A class of ring-shaped molecules that contribute nutty, caramel-like aromas. Hydroxymethylfurfural (HMF) is one of the most studied. It forms when fructose dehydrates. HMF concentrations are sometimes used as an indicator of how much heat a food product has been exposed to.

Maltol and ethyl maltol: These contribute a sweet, jam-like flavor. They’re sometimes added to processed foods as flavor enhancers (you’ll see them on ingredient labels). In natural caramelization, they form as part of the pyrolysis process.

Caramel color polymers: The large brown polymers that actually create the characteristic color are a complex mixture of compounds. Different production conditions (temperature, pH, presence of ammonium compounds) produce different types of caramel color with different properties. Food manufacturers classify these as Class I through Class IV caramel colors, and they behave very differently in food applications.

The exact profile of compounds you get depends on temperature, time, the pH of your caramel, and which sugars you started with. This is why a carefully made artisan caramel tastes different from a commercial one, even if both are “just caramelized sugar.”