Chocolate Academy
Chocolate Bloom (Fat Bloom and Sugar Bloom) - Where It Comes From and How to Avoid It
A white or grey film on a bar, a praline or a glaze is one of the most commonly misread signs in chocolate work. Many people throw such a product away, assuming it has gone mouldy or off. In reality, bloom is a physical phenomenon linked to fat or sugar migrating to the surface - the chocolate is still perfectly edible, though it loses its shine, smoothness and some of its flavour.
In this guide we distinguish the two types of bloom, explain their mechanisms and give you practical rules to keep ADIKAM chocolate in perfect condition - from the storeroom to the finished product.
Two kinds of bloom - they are not the same
Although the visual effect can look similar, fat bloom and sugar bloom have completely different causes and call for different prevention. Identifying the type is the first step to preventing it.
| Feature | Fat bloom | Sugar bloom |
|---|---|---|
| Cause | Cocoa butter migrating to the surface | Moisture dissolves the sugar and carries it to the top |
| Appearance | A grey, greasy, soft film - like a haze | White, dry, rough sugar crystals |
| To the touch | Smudges under the finger, vanishes with the warmth of the hand | Rough, gritty, does not vanish |
| Main enemy | Temperature swings, poor tempering | Moisture and condensation |
Where fat bloom comes from
This is the most common problem. Cocoa butter that is not stably crystallised (form V) gradually moves towards the surface, where it forms large, unstable crystals visible as a grey veil.
The most common causes
- Poor tempering - unstable form IV crystals transform over time, carrying fat to the top.
- Temperature swings - storing it now warm, now cool, causes the fat to melt and recrystallise on the surface.
- Contact with heat - leaving the product by a window, an oven or in a hot car.
- Fat migration from the filling - in nut pralines, fat from the filling seeps into the shell.
Where sugar bloom comes from
Here the culprit is moisture. When water settles on the surface of the chocolate - most often through condensation - it dissolves the sugar. Once the water evaporates, the sugar recrystallises as a rough, white deposit.
The classic condensation scenario
- You take the chocolate out of the fridge and unwrap it straight away - moisture from the air condenses on the cold surface.
- You store it in a humid room (above 65% relative humidity).
- You pack a warm, freshly coated product into airtight packaging, where the steam condenses.
How to avoid bloom - the storage rules
Prevention comes down to three pillars: a stable temperature, low humidity and proper tempering. Below are the conditions we use and recommend.
| Parameter | Recommended value | Why |
|---|---|---|
| Temperature | 15-18°C (stable) | Prevents the fat from melting and recrystallising |
| Relative humidity | below 55% | Protects against sugar bloom |
| Packaging | Airtight, odour-proof | Chocolate absorbs moisture and foreign aromas |
| Keep away from | Sun, spices, heat sources | Swings and the taking-on of odours |
Practical everyday tips
- Store chocolate in a dry, dark place at a stable temperature - not in the fridge unless you have to.
- If you must chill it, pack the product airtight and, after taking it out, let it come up to room temperature BEFORE opening the packaging - this is key against condensation.
- Always temper chocolate before filling moulds and coating - stable crystals are the best protection against fat bloom.
- Keep callets away from flour, coffee and spices - cocoa butter absorbs aromas.
Frequently asked questions
Is bloomed chocolate safe to eat? Yes, bloom is a visual and flavour flaw, not a health one. Such chocolate is safe - it is especially good for baking and hot chocolate, where it melts anyway.
Can I "fix" bloomed chocolate? Bloom cannot be reversed on a finished product, but by melting and properly re-tempering the chocolate you will recover a smooth, glossy structure.
Why do callets bloom less often than bars? Callets in their sealed, original packaging and kept in stable conditions are well protected. Bloom usually appears after improper processing or storage.
