In this article, Chef Prish explains the different styles of machines used to grind and conche chocolate at home. She discusses the features, pros and cons of stone melangers, wet grinders, roller mills and more.
In her previous article how to make chocolate with cocoa beans (bean to bar), Chef Prish discussed the chocolate conching and grinding process, grinding science and cocoa particle size in depth. For a detailed explanation, we recommend you jump over to that article. Below is a quick summary to give context for her discussion on chocolate grinding and conching machines:
- Cocoa particles are measured in micrometers (aka microns, or μm).
- The lower the μm, the more refined the chocolate is.
- The higher the μm, the coarser the chocolate is.
- In chocolate-making the ideal cocoa particle size (μm) varies by country, ranging from 10 μm to 30 μm. This is outlined in the table below.
| Cocoa particle size | Notes |
|---|---|
| 35 μm and over | Coarse, granular. Human tongue can detect cocoa grains |
| 30 μm | American chocolate |
| 12-25 μm | European chocolate |
| 10 μm | Japanese chocolate |
| 10 μm and under | Over-refined. Unpleasant gummy, waxy mouthfeel. |
What Machinery Should You Use to Grind and Conche Chocolate?
| Machine | Pros | Cons |
|---|---|---|
| Stone Melanger | 15-25 μm particle size Capable of both grinding and conching* | |
| Wet Grinder (aka Indian Spice Grinder) | 15-25 μm particle size Affordable Capable of both grinding and conching* | Less durable |
| Ball Mill | 15-25 μm particle size | Incapable of conching (grinding only)* Expensive |
| Roller Mill | Up to 25 μm particle size | Incapable of conching (grinding only)* Expensive |
| Stone Metate | Long lasting Reliable, consistent Affordable | Labor intensive |
Research shows that ball mills produce the most consistent liquor, are the easiest and most affordable to maintain, and last the longest. Ultimately, you want to use what you are most comfortable with and what is most reasonable for your needs.
Stone Melanger
To grind cocoa, you can use stone grinders or melangers, which are stainless steel drums with two rotating granite wheels positioned in the middle of the drum on a stone slab. They spin to crush and refine the particles over 24 – 72 hours. You can expect liquor ranging from 15 – 25 μm depending on how old the machine is, and the duration of grinding.
When purchasing a melanger, make sure the motor runs on copper wiring instead of low-grade aluminum. Also, check the quality of the granite wheels. Good quality granite should be uniform in color and texture. It should be hard and dense and emit a clear, ringing sound when struck. Cocoatown is a universally popular brand. You can find a selection of equipment for home-to-professional use on their site.
COST: Stone melangers are expensive but still accessible for serious home chocolate-makers. For the entry level melangers from Cocoatown, expect to pay $600-1,200.
Wet Grinder/ Indian Spice Grinder
Wet grinders or Indian spice grinders are used to grind spices, grains, pulses, and nuts into powders, batters, or milk. They work exactly like stone melangers and some chocolate makers swear on them for grinding to conching, but others say they don’t have the durability to grind and conch for several days at a time.
COST: Wet grinders are affordable and easy to find from Indian supermarkets and even Walmart. Expect to pay $300-500.
Ball Mills
Ball mills refine liquor to between 15 – 25 μm. They are steel cylinders with water jackets around them. They contain 80,000 tiny steel or ceramic balls ( 9 – 10mm each) inside, which when heated up, grind and refine the cocoa to liquor. The ground cocoa is sucked through a pump at the bottom of the drum and fed back into the drum at the top, to be refined over and over again.
A shaft with protruding arms along the middle of the drum constantly agitates the cocoa around the tiny steel balls. When the water gets too hot, it is automatically drained and new water is filtered in. Ball mills also have a vent for acetic acid to be sucked out. Ball mills can be small enough to use at home and large enough for industrial use. Read more about the different kinds of ball mills here.
COST: Ball mills are usually expensive, large scale machines used for commercial chocolate production. Smaller styles suitable for home use may exist, but are difficult to find.
Roller Mills
Roller mills work in a similar way to stone melangers, except the rolls are placed flush against each other, from the largest gap at the top, to smallest at the bottom. They are made of steel or ceramic stone and are designed to refine cocoa to 25 μm. With additional rolls, the fineness can be further enhanced. Heat temperatures are controlled through a water cooling system and the cocoa particles can only move between the rollers if they reach a specific size at each roller. Read more about roller mills here.
COST: Roller mills are usually expensive, large scale machines used for commercial chocolate production. Smaller styles suitable for home use may exist, but are difficult to find.
Stone Metate
The stone metate is the OG of grinders, dating back to the early archaic period, (8,500 BP – 5,500 BP). The metate is a warmed stone slab on which grains and seeds are crushed to powder or paste with a heavy stone pestle. Although labor-intensive, they are still used today to create cocoa liquor by some artisanal makers.
COST: Stone metates are reasonably priced and can be found online at Amazon, eBay, Etsy and specialty stores. Expect to pay $200-500.
Final Thoughts
We hope this short piece from Chef Prish has given you a good overview of the best machines to grind and conche chocolate at home.
After this, you may still be wondering:
Do I REALLY need a special machine to grind and conche chocolate?
Can’t I just use what I already have at home?
If this is you, then you might like to consider this quote from Chef Prish in her earlier article How to make chocolate from cocoa beans: “Unfortunately, a blender or processor does not conch chocolate. The lowest micron reported is 90 μm…”
Not to mention, for the conching process you also need to leave the machine running for 4 days. It is very unlikely you would find a food processor or blender that you could operate for 4 hours at a time, let alone 4 days, without burning out the motor.
Therefore, if you’re serious about making chocolate from scratch, it leaves very little option other than to purchase a dedicated chocolate grinder and chocolate conche. To cut your costs, try to find a machine that is capable of both grinding and conching chocolate, such as a stone melanger or wet grinder. This way, you don’t have to purchase and maneuver two different machines.
If you aren’t ready to invest in one of these machines and you don’t mind a coarse chocolate, lastly, you could try to grind and conche the chocolate by hand using a mortar and pestle. It is certainly possible, just don’t expect a smooth chocolate like you would get from the store… and be prepared for a heavy arm workout!
Happy Chocolatiering!
