Chocolate bloom is the dull, greyish-white film that appears when cocoa butter or sugar migrates to the surface and recrystallises there. It is not mould, it is not spoilage, and the chocolate is safe to eat.
It is a cosmetic fault, and in most cases a reversible one: bloomed couverture re-tempers normally and performs exactly as it should. What it costs you is appearance, which matters if the piece is going in a box, and nothing at all if it is going into a ganache.
The two kinds of bloom
Fat bloom — the common one
Cocoa butter separates from the mass, rises to the surface and sets in unstable crystal forms. You get a grey haze, sometimes pale streaks or blotches, and the surface feels slightly soft rather than glassy.
Causes: temperature swings, storage above about 20 °C, poor tempering in the first place, or simply time.
Sugar bloom — the one you cannot fix
Moisture condenses on the surface, dissolves the sugar at the top layer, then evaporates and leaves sugar crystals behind. The result is a gritty white film that feels rough to the touch.
Cause: condensation. Almost always from refrigeration, or from moving chocolate straight from a cold room into a warm humid kitchen.
Sugar bloom does not re-temper away. The sugar structure at the surface has changed. This is the one to actually avoid.
How to tell bloom from mould
Customers ask this constantly, and the distinction is easy.
Bloom is flat, even, greyish-white, and follows the surface. It has no smell. It wipes to a smear rather than lifting off.
Mould is fuzzy, three-dimensional, often coloured green or blue-grey, and grows in distinct spots. It smells musty.
Chocolate is a very poor host for mould — there is almost no free water in it. If you are looking at a white film on couverture, it is bloom.
What bloom looks like against a good finish
Side by side the difference is obvious: one surface reflects light, the other absorbs it. Same chocolate, same recipe — only the crystal structure at the surface has changed.
Preventing it
Store at 12–20 °C. Stable is more important than cold. A steady 20 °C beats a cupboard that swings between 15 and 26.
Keep it sealed. Humidity below 50% if you can measure it. Chocolate also absorbs surrounding odours readily — store it away from onions, spices and cleaning products.
Do not refrigerate. This is the single most common cause of sugar bloom in home and small-kitchen use. If you must refrigerate, seal the chocolate airtight and let it come to room temperature before opening the bag, so condensation forms on the outside of the packaging instead of on the chocolate.
Temper properly. Well-tempered chocolate holds its finish for months. Badly tempered chocolate blooms within days, because the unstable crystals were there from the start.
Keep it out of light. Direct sunlight both warms and degrades the fat.
Bloom and summer shipping in Canada
This is worth being direct about. Couriers do not run refrigerated vehicles, and a parcel sitting in a truck or a depot in July can reach well above 30 °C. Chocolate softens, the cocoa butter migrates, and it re-sets bloomed.
The chocolate is still perfectly usable. It will re-temper and perform normally. But if you are ordering for a display piece or a boxed gift, plan around the weather rather than hoping.
Practical measures: order early in the week so nothing sits over a weekend, choose insulated packaging in high summer, and if you are in the GTA, collect in person. Pickup removes the entire risk and costs nothing. Our summer buying guide covers this in detail.
Can you use bloomed chocolate?
Yes, in almost every application.
- Melting, ganache, mousse, baking — no impact whatsoever. The bloom disappears the moment it melts.
- Re-tempering for moulding or enrobing — works normally. Melt fully to 45 °C and temper as usual; the finish comes back.
- Eating as-is or selling as a finished piece — the flavour is unaffected but the appearance is not saleable, and the texture can feel slightly grainy on the tongue.
The only real loss is presentation. Nothing goes in the bin.
Related reading
- Buying chocolate in summer: a Canadian guide — how we ship between May and September
- How to temper chocolate: the 45–27–31 method — bringing a bloomed batch back
Antalia Wholesale is an authorized Canadian distributor of the Barry Callebaut Group — Callebaut, Cacao Barry and Van Leer. We hold couverture in climate-controlled storage in Concord, Ontario, ship insulated through the summer months, and offer free pickup.
