What does conching do to chocolate?

Conching performs three functions: it shapes particles (rounding sharp edges to reduce viscosity), removes volatile compounds (acetic acid and other volatile acids evaporate during agitation), and distributes fat evenly through the mass (coating all particles with a uniform cocoa butter film). Together these changes create the smooth, flowable texture and developed flavor of finished chocolate.

How long should you conch chocolate?

Nanci at Chocolate Alchemy identifies 8 hours as the most interesting flavor point, approximately 30 hours as the optimal balance, and diminishing returns after 30 hours. Industrial conching with modern equipment takes 8–24 hours. In a craft melanger where refining and conching happen simultaneously, running 18–30 hours covers both the refining and optimal conching windows.

What is the difference between refining and conching?

Refining reduces particle size through mechanical pressure. Conching develops flavor through oxidation, volatile removal, and fat distribution through mechanical agitation. In industrial production these are separate steps with separate equipment. In a craft melanger, both happen simultaneously — the granite rollers reduce particle size while the agitation drives volatile evaporation and fat distribution.

What are the industrial conching temperatures?

Dark chocolate conching is 60–80°C. Milk chocolate runs at 45–55°C. White chocolate runs at 40–50°C. The lower temperatures for milk and white chocolate prevent heat damage to milk proteins and sugars. Craft melanger conching typically runs at 40–50°C from friction alone — below the industrial dark range but effective with longer running times.

What happens if I stop conching too early?

Under-conched chocolate retains more volatile acids and has a sharper, more acidic character. Particle shape remains irregular with sharp edges, creating higher viscosity for the same particle size. Fat distribution may be incomplete, producing a less homogeneous mouthfeel. A vinegary or acidic note in finished chocolate often traces to insufficient conching time.

Should I add sugar early or late in a melanger run?

Dandelion Chocolate's observation is that adding sugar freezes the current flavor state — conching slows significantly at the moment of sugar addition. Adding sugar early (4–6 hours) preserves more brightness and acid. Adding sugar later (12–16 hours) allows more pre-sugar acid removal. The choice depends on whether you want the final bar to be brighter or rounder in character.

Conching Chocolate: What It Does and How Long

Conching performs three functions: it shapes particles, oxidizes and removes volatile aromatics, and ensures homogenous fat distribution through the chocolate mass. In a craft melanger, conching and refining happen simultaneously. Most of the conching effect occurs after 8 hours, with the optimal flavor balance around 30 hours and diminishing returns beyond that point.

What Conching Actually Does

The word “conching” comes from the shell-shaped machines (conche — from Spanish for shell) that were the original format. The modern process retains the name but not the specific equipment. What matters is the three functions, which any sustained mechanical agitation in the presence of heat achieves.

Function 1 — Particle shaping: Mechanical agitation rounds off sharp particle edges, which reduces viscosity and improves mouthfeel. Sharp-edged particles of equal average size create more friction than rounded particles. This is why conched chocolate flows better and feels smoother than under-conched chocolate at the same particle size measurement.

Function 2 — Volatile removal: Undesirable volatile compounds — primarily acetic acid, other short-chain fatty acids, and aldehydes — evaporate from the warm mass during agitation. This is why running the melanger with the lid off during conching speeds acid removal. Fresh chocolate mass from a recently finished fermentation and roasting still carries residual acid that needs to be driven off.

Function 3 — Fat distribution: Cocoa butter is redistributed evenly throughout the mass, coating all particles with a uniform fat film. This fat coating is what gives chocolate its characteristic flow behavior — the fat-coated particles slide past each other, which is the physical basis of chocolate’s unique texture.

The Three Industrial Conching Phases

Industrial conching uses dedicated conching equipment through three distinct phases:

Dry phase: The chocolate mass is in a crumbly, powder-like state. Temperature for dark chocolate is 60 to 80°C (140 to 176°F). For milk chocolate: 45 to 55°C (113 to 131°F). Duration: 4 to 12 hours in modern equipment. This phase accomplishes the most acid and moisture removal. The high temperature accelerates volatilization, and the low fat content (only the naturally present cocoa butter, no additional fat added yet) creates maximum surface exposure for evaporation.

Pasty phase: Additional fat is partially added, bringing the mass from crumbly to pasty. Continued flavor development. Duration: 2 to 6 hours.

Liquid phase: Remaining fat and lecithin are added, bringing the mass to its final pourable viscosity. Final viscosity adjustment. Duration: 1 to 4 hours.

Industrial conching total time: Modern efficient conches complete in 8 to 24 hours. Early conching (Rudolf Lindt’s original machines in 1879) ran for days. Modern high-shear conching equipment achieves equivalent results faster.

Conching in a Craft Melanger

In a craft melanger, you do not have separate conching phases. Refining and conching happen simultaneously because the granite rollers both reduce particle size and provide the mechanical agitation that drives conching.

This has implications for how you manage the process:

The refining and early conching happen together in the first 0 to 12 hours. By 12 hours, particle size is approaching the target range and the first conching effects (acid removal, initial fat distribution) are well underway.

The later conching — flavor development, additional acid removal, final fat distribution — continues from 12 to 30 hours. This is the window where leaving the lid off produces measurable flavor differences by allowing volatile evaporation.

Nanci’s flavor benchmarks for craft melanger conching:

At 8 hours: The most interesting flavor state. Bright, fruity, complex, slightly sharp. For some origins and style preferences, this is the right stopping point.
At approximately 30 hours: The optimal balance. Volatiles reduced, fat distribution complete, particle size in target range. Most finished bars fall in this window.
After 30 hours: Diminishing returns. Flavor becomes flatter; the interesting volatile complexity that was being reduced is largely gone.

How Adding Sugar Affects Conching

Dandelion Chocolate’s observation about sugar addition is useful for craft makers: adding sugar to the melanger appears to “freeze” the flavor state at that moment. The flavor development that was in progress stops or slows significantly at the point of sugar addition, and then the flavors that were present at that moment are what you taste in the finished bar, developed further by subsequent conching.

This means timing of sugar addition is a variable you can use. Adding sugar early (at 4 to 6 hours) locks in the chocolate’s flavor at a point with more volatile acid and brightness. Adding sugar later (at 12 to 16 hours) gives more pre-sugar conching time for acid reduction before locking in the flavor baseline.

Temperature During Conching

Industrial temperature guidelines by chocolate type:

Dark chocolate conching: 60 to 80°C. Milk chocolate conching: 45 to 55°C. White chocolate conching: 40 to 50°C. The lower temperatures for milk and white are required because milk proteins and sugars are heat-sensitive — the higher temperatures used for dark would cause off-flavors through non-enzymatic browning of milk solids.

In a craft melanger, temperature is not independently controlled. The mass generates heat through friction, typically reaching 40 to 50°C during active refining. This is below the industrial dark chocolate conching range (60 to 80°C), which means craft conching at melanger temperatures is gentler and requires more time to achieve comparable acid removal.

Moisture During Conching

Moisture targets through the industrial process:

Before conching: approximately 1.5 to 2% moisture
After conching: less than 0.5 to 1.0% (Beckett Science)
Industrial target: less than 0.5% (Beckett Industrial)

Moisture reduction is one of the key outcomes of conching. The evaporation of water during the dry phase removes moisture that would otherwise cause viscosity problems in the finished chocolate. Even 0.1 to 0.5% water dramatically increases yield value by dissolving sugar surfaces and causing particles to stick.

For the mechanical context of how the melanger refines and conches simultaneously, see our melanger refining guide. For how conching affects the final texture described by viscosity models, read our article on chocolate viscosity troubleshooting. For measuring particle size during conching, see our grindometer guide.

JayArr Chocolate

Industrial Three-Phase Conching

	Mass State	Temp (Dark)	Temp (Milk)	Duration	Primary Effect
Dry phase	Crumbly powder	60–80°C	45–55°C	4–12 hours	Maximum acid/moisture removal
Pasty phase	Thick paste	60–80°C	45–55°C	2–6 hours	Continued flavor development
Liquid phase	Pourable liquid	60–80°C	45–55°C	1–4 hours	Final viscosity adjustment

Craft melanger combines all three phases simultaneously; typical run: 18–30 hours

Frequently Asked Questions

What does conching do to chocolate?: Conching performs three functions: it shapes particles (rounding sharp edges to reduce viscosity), removes volatile compounds (acetic acid and other volatile acids evaporate during agitation), and distributes fat evenly through the mass (coating all particles with a uniform cocoa butter film). Together these changes create the smooth, flowable texture and developed flavor of finished chocolate.
How long should you conch chocolate?: Nanci at Chocolate Alchemy identifies 8 hours as the most interesting flavor point, approximately 30 hours as the optimal balance, and diminishing returns after 30 hours. Industrial conching with modern equipment takes 8–24 hours. In a craft melanger where refining and conching happen simultaneously, running 18–30 hours covers both the refining and optimal conching windows.
What is the difference between refining and conching?: Refining reduces particle size through mechanical pressure. Conching develops flavor through oxidation, volatile removal, and fat distribution through mechanical agitation. In industrial production these are separate steps with separate equipment. In a craft melanger, both happen simultaneously — the granite rollers reduce particle size while the agitation drives volatile evaporation and fat distribution.
What are the industrial conching temperatures?: Dark chocolate conching is 60–80°C. Milk chocolate runs at 45–55°C. White chocolate runs at 40–50°C. The lower temperatures for milk and white chocolate prevent heat damage to milk proteins and sugars. Craft melanger conching typically runs at 40–50°C from friction alone — below the industrial dark range but effective with longer running times.
What happens if I stop conching too early?: Under-conched chocolate retains more volatile acids and has a sharper, more acidic character. Particle shape remains irregular with sharp edges, creating higher viscosity for the same particle size. Fat distribution may be incomplete, producing a less homogeneous mouthfeel. A vinegary or acidic note in finished chocolate often traces to insufficient conching time.
Should I add sugar early or late in a melanger run?: Dandelion Chocolate's observation is that adding sugar freezes the current flavor state — conching slows significantly at the moment of sugar addition. Adding sugar early (4–6 hours) preserves more brightness and acid. Adding sugar later (12–16 hours) allows more pre-sugar acid removal. The choice depends on whether you want the final bar to be brighter or rounder in character.