How to store chocolate, and what that white film means

The four enemies

Heat. Above the storage range a bar softens and loses its gloss, and once it passes the melting point of its cocoa butter crystals it loses its temper. In a warm car it can melt outright.

Moisture. Water on the surface dissolves sugar, which recrystallizes as a dusty white film. Callebaut sets 70 percent relative humidity as the upper limit for storage.

Light. Sunlight warms the bar and can stale the fats over time.

Smells. Cocoa butter soaks up odors. A bar stored next to coffee, spices, onions or a scented candle will taste like them.

Why not the fridge

A fridge is cold, which is good, and humid and smelly, which is not. The bigger problem is coming out: a cold bar in a warm kitchen collects condensation, and that water causes sugar bloom.

If you live somewhere really hot with no cool spot, the fridge is better than a melted bar. Wrap the chocolate airtight, put it in a sealed container, and let it come all the way back to room temperature before you open the wrapper. Callebaut gives the same advice for its own products.

Fat bloom and sugar bloom

Fat bloom is the common one. Warmth melts some of the cocoa butter, which moves to the surface and sets again in a less stable crystal form. You get gray streaks or a soft, matte haze that smears when you rub it. Even a perfectly stored bar can slowly bloom over many months as its cocoa butter drifts from Form V to the more stable Form VI.

Sugar bloom comes from moisture. It looks like a dry, dusty white coating that does not smear, and it feels slightly gritty. Usually it means condensation, most often from a trip out of the fridge.

Both are cosmetic. The bar may feel a little drier or crumblier, and the flavor is usually fine.

Fixing a bloomed bar

You cannot un-bloom a bar at room temperature, but you can rescue it. Melt it gently and either temper it again (see the tempering guide) or simply use it: brownies, a ganache, hot chocolate, chocolate sauce over fruit. Melting resets the crystals completely, and nobody will know.

Sugar-bloomed chocolate melts fine too. It just may seize a little if there is a lot of water, so add it to something with fat or liquid in it.

How long a bar keeps

Dark chocolate keeps well because it holds almost no water. Go by the maker's best-by date on the wrapper. In our experience a bar tastes its brightest in the first months, and the fruity origins fade a little sooner than the roasty ones.

Once opened, fold the wrapper back tightly or move the bar to a sealed container. Opened bars pick up smells and moisture faster. A good bar rarely lasts long enough for this to matter.

Gifting and travel

A bar in a suitcase is safe in winter and a gamble in July. Pack it in the middle of your clothes, away from the outside walls of the bag, and keep it out of the trunk of a parked car. Hard cases help, since a bar that cracks in transit is still delicious but a little sad to hand over.

For a gift, give it soon after you buy it and tell the person where to keep it. A two-ingredient bar from a named farm with a note about the origin is a better present than a big box of anything.

Shipping and summer

Craft makers often pause or change shipping in hot months. Ritual Chocolate ships only Monday through Thursday so bars do not sit in a warm depot over a weekend, and many makers add cold packs in summer. If a parcel arrives soft, put it somewhere cool, flat, and leave it alone for a few hours before opening. It will likely bloom, and it will still taste good.