Chocolate science: cocoa butter crystals
Advanced Kitchen science
Why chocolate snaps, shines or turns streaky and soft, depending on how its fat crystallizes as it cools.
Written with AI help from the sources listed, and published by Cory. Spot a mistake? Tell us and we'll fix it.
How do you do it?
- Melt chocolate gently, under about 115-120°F for dark, and less for milk and white.
- Keep every drop of water and steam out of melting chocolate.
- If it does seize, stir in a spoonful or more of warm cream or oil and use it as a sauce.
- Store chocolate airtight at a cool room temperature, about 60-70°F, not in the fridge.
- Chocolate chips and coating chocolate are formulated for baking and dipping without tempering.
Why does it work?
Cocoa butter can set into six different crystal forms. Only one, often called form V, packs tightly enough to give glossy chocolate that snaps cleanly and melts right at body temperature. Melt chocolate and let it cool on its own and you get a jumble of looser crystals: dull, soft and streaky. Tempering melts every crystal, then cools and rewarms the chocolate so mainly form V forms. Gray streaks on old chocolate are fat bloom, cocoa butter that melted and re-set badly. A white, dusty film is sugar bloom, sugar pulled out by moisture. A few drops of water make the sugar and cocoa particles clump into a stiff paste; that is seizing.
What are the common mistakes?
- Overheating in the microwave — scorched, grainy chocolate; heat in 15-30 second bursts and stir.
- Chilling chocolate in the fridge — it sweats when it comes out, causing sugar bloom.
Still stuck? Watch someone do it on YouTube.
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