Today’s chocolate labels have so much more information on them than they used to. It used be that the only description on a bar of chocolate would be whether it was milk or dark. With today's artisan chocolate bars, you have a wealth of information on every step of the process, from where the beans were grown to how the chocolate was made.
The short answer is that the lower the percentage, the sweeter the bar will taste. When you subtract the percentage on a label from 100%, that’s how much of the bar is mostly sugar. The actual percentage on a bar refers to cocoa mass, which is made up of two components: cocoa solids and cocoa butter. Cocoa solids give chocolate its distinct taste and color, while cocoa butter is a pale-yellow fat that is naturally found in the bean.
70% You now know that the 70% refers to the cocoa mass (cocoa solids and cocoa butter). What it doesn’t tell you though is how much cocoa solids and cocoa butter were added to make up the 70%. Sometimes chocolate makers add extra cocoa butter to their bars, which would then lower the amount of cocoa solids used. This is one reason why bars with the same percentages can taste very different from each other.
30% While this number mostly refers to the sugar content of a bar, it can also include a few other ingredients: vanilla, soy lecithin (an emulsifier), and the milk powder used to make milk chocolate. These ingredients are all optional, including the sugar, which is why you might see some bars labeled "100%."
Keep checking back for more answers to all of your chocolate questions! In the meantime, feel free to pick up some chocolate!