Why chocolate separates
Visible fat pooling on the surface or at the edge of a filling. Three causes, two of them recoverable.
If you read nothing else
Separation in a ganache is a broken emulsion and is recoverable. Separation in melted chocolate is added fat or scorching. On a stored bar it is bloom, and needs nothing.
In a ganache or filling
Visible fat means a broken emulsion. The cream's water phase can no longer hold the fat dispersed, and it has coalesced.
This is recoverable: a spoonful of warm liquid stirred in from the centre outward, or a stick blender, rebuilds it. Temperature shock and over-stirring are the usual triggers.
In melted chocolate
Pure chocolate has no water phase, so it does not separate in the emulsion sense. What looks like separation in a melting bowl is usually one of two other things.
Either an added fat — oil, butter — that is not miscible with cocoa butter at that temperature and is sitting on top. Or the beginning of scorching, where the mass has started to break down. The first can be stirred in and accepted as a permanent change; the second cannot.
In a stored bar
Fat at the surface of a stored bar is fat bloom, not separation, and it is cosmetic. See the bloom guide rather than treating it as a failure to fix.
Covered in this guide
- Making ganacheWhere the recoverable version happens.
- Chocolate has overheatedThe unrecoverable version.
- Chocolate has bloomedThe version that is not a failure at all.
Sources
- ChocolateHQ editorial synthesis — ChocolateHQ(citation identity confirmed; passage not re-read)
- The Science of Chocolate — Royal Society of Chemistry(citation identity confirmed; passage not re-read)