Does Cacao Go Off? Shelf Life, Bloom And Date Labels

Cacao does not go off in the way milk goes off. Dark chocolate and cacao carry a best before date rather than a use by date, and UK guidance is explicit that those mean different things: a use by date "tell[s] you when the food is no longer safe to eat", while a best before date "tells you when the food might start to reduce in quality". Past a best before, food is described as "usually safe to eat but may not be of the same quality".

What actually changes is flavour chemistry and surface appearance, and the category tends to conflate the two. The white film people throw chocolate away for is not mould and not rancidity. It is a crystal problem, and it has been measured.

What "best before" means on a chocolate label

The two date types are legally distinct in the UK. Official guidance puts use by dates in the safety category and best before dates in the quality category, and tells consumers they can judge food past a best before by sight, taste or smell. Dry, high-fat foods like dark chocolate sit in the best before group.

That is a statement about the format, not about any particular tube or bar. The date printed on the pack in front of you is the manufacturer's, set by their own stability work, and it is the only date that applies to that product.

What eighteen months of storage actually does

Roda and Lambri, writing in Nutrients in 2019, took six products supplied by a single Italian manufacturer — dark, milk and gianduja chocolate, plus cocoa mass, cocoa powder and hazelnut paste — and held them in their own packaging at 21 ± 2 °C and 65% relative humidity for eighteen months, the company's stated best before period. They sampled at five points eighteen weeks apart, ran analyses in triplicate across two independent rounds, and used a trained panel of eight assessors for the sensory work.

The composition moved a long way. Cocoa mass lost 64% of its polyphenols over the period and cocoa powder lost 87%, while vitamin E held up far better in those two, at 5% and 14% loss respectively. Gianduja chocolate went the other way, losing 86% of its vitamin E and 47% of its polyphenols. Peroxide values in the chocolates stayed in the range of roughly 5 to 11 meq O₂/kg throughout, which the authors describe as slow lipid oxidation.

On the panel, dark chocolate became grittier, more acidic and more bitter, with oxidation-related descriptors appearing from the third sampling point onward. Milk chocolate lost its nutty aroma but kept its sweetness. The authors conclude that the samples still scored well at eighteen months.

Three caveats before you lean on those numbers. Everything came from one manufacturer and one storage condition. The paper is internally inconsistent on toasted aroma, abstract against results. And it was funded by the company that supplied the samples.

Bloom is a crystal problem, not spoilage

The pale, dusty bloom on an old bar is cocoa butter rearranging itself. El Hadri and colleagues, in Applied Sciences in 2022, describe bloom as the loss of the original gloss leaving a more or less white surface, and attribute it to cocoa butter's crystal transformation from form V to form VI, stating that the transformation to form VI "is responsible for the development of fat bloom".

The paper is about mixtures rather than finished bars, but its timings are instructive. Citing earlier work, it reports bloom appearing after roughly two weeks in cocoa butter blended with anhydrous milk fat, against about twenty to thirty weeks once a cocoa butter equivalent was in the blend. Separately it notes a dark chocolate with 20% cocoa butter substitute resisting bloom after two weeks at 29 ± 1 °C, where a 5% substitute did not. Throughout, bloom is treated as a question of gloss and colour. Safety does not come up.

There is a second kind. Heuler and colleagues, writing in Scientific Reports in 2020, describe sugar bloom as being caused by moisture dissolving sugar and forming crystals at the surface of the chocolate. Their study bloomed three retail chocolates and characterised the surfaces spectroscopically; it does not report how much moisture, or how long, it takes.

Does cacao go off faster if you refrigerate it

Refrigeration is the common mistake. The sugar bloom route Heuler and colleagues describe needs moisture at the surface of the chocolate, and a fridge is the one place in a kitchen where a pack is routinely moved between a cold interior and a warm room. None of the studies cited here tested a domestic fridge, so read that as a reason to keep a tube sealed in a cupboard rather than as a measured comparison. An open pack in a fridge also sits beside everything else in there, which is its own reason to keep it closed.

Sealed, dark, steady and off the windowsill covers it. If you want the detail on why unprocessed and alkalised cacao behave differently in the first place, see our note on raw cacao and cocoa powder, and on sweeteners, coconut sugar and refined sugar in chocolate.

What is in a Chaski tube, and where the date is

Chaski Cacao is a 600 g tube of dark chocolate buttons at 77% cacao, with a daily dose of four buttons printed on the pack. The cacao is single-origin Peruvian and Ecuadorian, ground at low temperature, sweetened with coconut sugar. There are no emulsifiers, no seed oils, no palm oil and no added cane sugar in it, and every batch is tested for lead, cadmium and pesticides.

The date to go by is the one printed on your tube. Composition and format are listed on the Chaski Cacao product page, and the rest of the library sits in our guides.

If a tube has bloomed, look at the date, then smell it. That is the order the UK guidance suggests, and it is better than the bin.

Sources

1. GOV.UK, Understanding food labelling: best before and use-by dates
2. Roda A, Lambri M, Nutrients, 2019;11(11):2719
3. El Hadri M, Bresson S, Lecuelle A, Bougrioua F, Baeten V, Nguyen VH, Faivre V, Courty M, Applied Sciences, 2022;12(13):6594
4. Heuler J, He S, Ambardar S et al., Scientific Reports, 2020;10:9833