Preventing bloom
Temper properly and store at a stable temperature. Stability matters more than the number.
Fat bloom is unstable cocoa butter crystals converting over time and pushing fat to the surface. Sugar bloom is moisture dissolving surface sugar, which recrystallises visibly. Both are preventable and neither is spoilage.
For fat bloom, the two levers are temper and temperature stability. A properly tempered piece blooms far more slowly, and a cupboard swinging between 16°C and 26°C each day blooms chocolate faster than a steady 22°C does. Cycling is the enemy more than warmth is.
For sugar bloom, the lever is humidity — which is why the fridge causes it, and why chocolate taken out of one should be left wrapped until it reaches room temperature.
- What it is for
- To keep finished chocolate glossy and unbloomed for as long as possible.
- Working temperature
- 15–18°C — Ideal storage. Stability matters more than the exact figure — temperature cycling drives bloom faster than a steady warmer temperature.
- Works with
- Dark chocolate, Milk chocolate, Couverture
Method
1. Temper properly, and verify with a test strip before committing a batch.
2. Store sealed at a stable 15–18°C, away from light and from anything strongly scented.
Where people go wrong: Chasing a low temperature at the cost of stability. A steady warm cupboard beats a fluctuating cool one.
3. If refrigeration is unavoidable, wrap airtight and let the chocolate return to room temperature still sealed.
Where people go wrong: Unwrapping straight from the fridge, which condenses moisture onto the surface and causes sugar bloom.
When it goes wrong
| Symptom | Cause | Fix |
|---|---|---|
| Bloom appeared within days of making | Almost certainly a temper failure rather than storage. | Test the temper next time. Well-tempered chocolate stored properly takes months. |
Related
Works with
- Dark chocolateTemper properly and store at a stable temperature. Stability matters more than the number.
- Milk chocolateTemper properly and store at a stable temperature. Stability matters more than the number.
- CouvertureTemper properly and store at a stable temperature. Stability matters more than the number.
Covered in
- Preventing bloomThe full procedure.
- Humidity and chocolateWhat condensation produces, and how to avoid it.
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)