Ganache Ratios That Actually Work, and the Truffles They Make

Ganache is an emulsion of fat in water, which surprises people who assume it is a mixture of two fats. Cream is mostly water. Chocolate is mostly fat and sugar. Making ganache means dispersing cocoa butter droplets through the water phase of the cream and keeping them there. Once you think of it that way, both the ratios and the failures make sense.

The ratio is a fat balance, not a rule

The familiar advice, one part cream to one part chocolate by weight, is a decent default for a 55 to 60% dark chocolate used as a glaze. It falls apart the moment you change chocolate, because different chocolates carry wildly different fat loads. A 70% dark bar is roughly 40% fat. A milk chocolate is around 30 to 35% fat but adds milk solids and much more sugar. White chocolate can be 30% fat and 50% sugar, and it has no cocoa solids at all to give structure.

So the working ratios, chocolate to cream by weight:

Read those as starting points to test once, not gospel. Two 70% bars from different makers can differ by four or five percentage points of fat depending on how much cocoa butter was added back, which is enough to shift a filling from perfect to slightly loose. Our ganache ratio calculator does the arithmetic for any batch size and adjusts for butter and glucose additions.

Method that works every time

1. Chop the chocolate finely, or use callets. Large chunks melt unevenly and leave you overworking the mixture.
2. Bring the cream just to a bare simmer. Boiling reduces it, which changes your ratio behind your back.
3. Pour the hot cream over the chocolate and leave it, untouched, for two minutes. Patience here prevents most problems.
4. Start stirring from the centre with a spatula in small circles. A tight, glossy core will form. Widen the circles gradually until the whole bowl comes together.
5. Finish with an immersion blender held below the surface, tilted so it does not draw in air. Thirty seconds gives a noticeably smoother, more stable emulsion and a longer shelf life.
6. If you are adding butter, wait until the ganache is below 35 C. Butter added to hot ganache separates.

Why emulsions break, and how to fix one

A broken ganache looks oily, grainy or curdled, with visible fat separating out. Three usual causes: too much fat for the available water, temperature shock, or aggressive stirring that shears the emulsion apart before it forms.

The fix is almost always the same and it feels wrong: add more liquid, not more chocolate. Warm 15 to 30 ml of cream or whole milk, add it a little at a time to the broken mixture while blending with an immersion blender. The extra water phase gives the fat somewhere to disperse. If it is still broken, warm the whole bowl gently to about 35 C and blend again. Ganache is genuinely difficult to destroy permanently.

The optional ingredients and what they do

• Butter, 5 to 15% of chocolate weight. Adds richness and a softer bite at fridge temperature. Reduces shelf life slightly.
• Glucose or invert sugar, 5 to 10%. Binds water, which lowers water activity and both extends shelf life and keeps the texture from going grainy over time. Water activity, rather than total moisture, is the variable that governs whether a filling is shelf stable, and the National Center for Home Food Preservation at the University of Georgia publishes accessible material on how it is measured and why it matters. This is the single biggest difference between a shop ganache and a home one.
• Sorbitol or a small amount of alcohol. Same purpose, water binding, with the alcohol also contributing flavour and some preservation.
• Fruit purée in place of some cream. Delicious and much more perishable. Purées are more acidic and more watery than cream, so expect to raise the chocolate proportion and shorten the use-by date substantially.

From ganache to truffle

Chill the ganache in a shallow tray until firm but not hard, roughly two hours at 4 C. Scoop or pipe into balls, then roll quickly between cool palms. Chill again. Dip the centres in tempered chocolate, or roll them in cocoa powder for the classic rustic finish. If you are dipping, the centres must be at about 18 C, not fridge cold, or the shell will crack as the centre warms and expands.

Tempering the coating properly is what makes the difference between a truffle that keeps and one that goes grey in a day. The full method is in our guide to tempering chocolate at home.

Shelf life, honestly

A plain cream ganache without added glucose or preservative keeps three to seven days refrigerated. With glucose and a fully enclosed tempered shell, a professional bonbon typically gets two to four weeks. Anything with fresh fruit is shorter still. Water activity is the governing variable and home cooks have no way to measure it, so err short.

Treat ganache as the perishable dairy product it is. Keep it refrigerated, do not leave it at room temperature for extended periods, and follow ordinary cold-holding practice of the kind the FDA sets out for foods containing cream. Consumer-level storage and time-temperature guidance is collected at FoodSafety.gov. If you are selling what you make, your state or county health department will have cottage food rules that specifically address filled confections, and they are worth reading before you take orders.