Ganache is an emulsion: droplets of water from the cream dispersed through a continuous fat phase of cocoa butter, or the reverse, depending on the proportions. An emulsion is unstable by nature; it has to be created and then held. When people say a ganache has split, what they mean is that the emulsion has broken: the fat has separated and risen in shiny beads, and the mass has gone grainy.
There are exactly three causes, and all three are mechanical rather than a matter of formula.
One: temperature
Cream and chocolate have to meet in a narrow band. The optimum for combining is 35–40 °C for both.
Cream that is too hot, above 50 °C, overheats the cocoa butter: it melts completely and loses the ability to hold structure. The mass looks thin and shiny, and it splits as it cools.
Cream that is too cold will not melt the chocolate fully — microcrystals remain, and an emulsion will not form around them. The mass is grainy from the outset.
The practical move: bring the cream almost to the boil, then let it fall to 40 °C and only then pour it over the chocolate. Not the other way round.
Two: the order and technique of mixing
The cream goes in in three additions rather than all at once, and it is worked from the centre.
The first third creates the core of the emulsion: a thick, elastic, glossy mass appears in the middle of the bowl. This is the decisive moment — if the core has formed, the emulsion will only grow from there. The sign of a proper core: the mass trails behind the spatula and looks satiny rather than thin.
The second and third additions go into that core gradually, in circular movements from the centre outward. Pour it all in at once and there is too much fat relative to water in any given volume, and the emulsion never forms at all.
Work it with a spatula, not a whisk: a whisk beats in air, which has no place in a ganache and will show up later as bubbles in the bonbon.
Three: the ratio of fat to water
Each type of chocolate needs its own quantity of cream, because each carries a different amount of cocoa butter and dry solids.
| Chocolate | Chocolate to cream by weight |
|---|---|
| Dark, 60–70 % | 1 : 1 |
| Milk | 2 : 1 |
| White | 3 : 1 |
The logic is simple: the more cocoa butter and the fewer dry solids a chocolate carries, the more water it can bind. White chocolate has plenty of cocoa butter and no cocoa liquor at all — so it needs three times less cream, or the emulsion simply cannot hold that much water.
Swapping dark for white at the same ratio is the single most common cause of a hopelessly split ganache.
How to bring a split ganache back
The good news: it is almost always recoverable, and one move does it.
Bring the mass to 35–40 °C — no higher — and blend it with a stick blender. Hold the head near the bottom, tilt the jug, keep the speed at minimum so as not to beat in air. The emulsion re-forms within seconds and the mass turns satiny as you watch.
If the blender does not do it, add a little warm liquid — 5 to 10 % of the mass — and blend again: splitting is often caused by simply not having enough water phase.
The only unrecoverable case is overheating past 50 °C with visible oil separation: the cocoa butter has already lost its structure.
What sets the shelf life
Not the chocolate but the water. More precisely, water activity — the proportion of free, unbound moisture available to micro-organisms.
The more cream, the shorter the life of the filling. Working figures for storage at 16–18 °C:
- Classic ganache on cream at 1:1 — two to three weeks.
- Ganache with added butter — up to four weeks: fat displaces water.
- Ganache with invert sugar or glucose syrup — up to six weeks: they bind free water.
- Ganache with fresh fruit purée — five to seven days, regardless of everything else.
Hence the practical conclusion: a bonbon lives exactly as long as its filling lives. A dark chocolate shell would last months, but a pale film will appear on it long before that — and that is another story.
Working with ganaches and filled bonbons is covered across the chocolate masterclasses.