One number, one job
The percentage on a chocolate bar measures total cocoa content — everything in the recipe that came from the cacao bean: cocoa solids and cocoa butter combined. In a 70% dark chocolate, roughly 30% of the bar is everything else, and in most cases that remainder is almost entirely sugar. Salt, vanilla or emulsifiers might account for a fraction of a percent; the rest is sweetness.
That's genuinely useful. It gives you a rough sense of how sweet a bar is likely to be, and it allows manufacturers to meet the minimum legal thresholds that determine what can be sold as chocolate in the UK. But sweetness isn't the same as flavour, and this is where the percentage figure starts to mislead.
Why two 70% bars can taste nothing alike
Pick up any two dark chocolate bars marked at 70% and they will likely taste quite different — one fruity and bright, another bitter and roasted, a third almost mellow. The percentage hasn't changed; the beans, the roast and the process have.
Bean origin shapes flavour more dramatically than almost any other factor. Cacao grown in different regions — distinct soils, climates, fermentation traditions — produces entirely different flavour profiles even at identical cocoa percentages. The roast then shifts things further: a lighter roast preserves more of the bean's natural acidity and fruit notes, while a heavier roast drives those off and introduces deeper, more bitter tones. Then there's conching — the long, heated mixing process that smooths and develops the chocolate — which can run for hours or days depending on the maker's intention, altering both texture and the way flavour lingers.
None of that appears in the percentage. The number on the front of a bar is a compositional fact, not a flavour forecast.
Higher percentage does not mean better chocolate
There is a widespread assumption that a higher cocoa percentage signals a more serious or sophisticated product. It doesn't. It signals less sugar. Good chocolate exists across the entire range — from milk chocolate bars in the low thirties to bars pushing 90% and beyond — and a high percentage on a poorly sourced, quickly processed bar will not save it.
A bar made with care from well-fermented, well-roasted beans will outperform a rushed higher-percentage one in almost any sensory comparison. The craft behind the number is what deserves attention, not the number itself.
Very high percentages — above 85% or so — can also narrow the field of who enjoys them, because the balance tips decisively away from sweetness into territory that takes some acclimatisation. That is neither good nor bad; it depends on what you are serving and to whom.
Where milk chocolate fits in
Milk chocolate percentages run lower than dark because the recipe includes milk solids, which occupy the recipe in the same way cocoa does. A milk chocolate at 40% is not a diminished version of a 40% dark — it is a structurally different product with its own character. UK regulations set minimum cocoa thresholds that must be met before a product can legally be labelled as chocolate, so even at the lower end of the percentage scale there is a floor below which the label changes.
White chocolate contains cocoa butter but no cocoa solids, so any percentage shown refers to cocoa butter content alone — which explains why its flavour sits so far from anything conventionally recognised as chocolatey.
How to use the number sensibly
Use the percentage to orient yourself: to understand roughly how sweet a bar will be, and to compare like with like within a single maker's range. Beyond that, look for information about origin, read how the maker describes the bar, and taste before committing to quantity.
The bean-to-bar and single-origin movements have done more to improve the quality of chocolate available in Britain than any percentage competition ever could. What those makers share is not a particular number on the wrapper — it is attention to every stage between harvest and finished bar, most of which is invisible once the foil is on.
