Chocolate: a question of percentages

Master baker and chocolate guru Alice Medrich calls for chocolates with specific cacao percentages, all in an effort to balance flavor and texture. We asked Alice what the percentages mean and why you should care.

Q.What exactly are cacao percentages?

A.The cacao percentage on a chocolate bar indicates the percentage of the bar (by weight) that is pure cacao, or cocoa bean. Cocoa beans are composed of cocoa butter (fat) and dry cocoa solids (think fat-free cocoa powder).
Since the best bittersweet and semisweet chocolates are composed almost entirely of cocoa beans (often including some extra cocoa butter) and sugar, with just tiny amounts of optional vanilla and lecithin, the cacao percentage indirectly tells us the sugar content as well: A bar of semisweet or bittersweet chocolate marked 55% cacao therefore contains 45% sugar, while a bar labeled 70% cacao contains 30% sugar.
As the cacao percentage increases, the chocolate itself will taste more intensely chocolatey and less sweet. The effect on recipes is a little more complex, however, because cacao percentage affects texture as well as the flavor and sweetness of cakes and desserts.

Q.Why do these recipes call for chocolates with specific cacao percentages?

A.Not even 10 years ago, most bittersweet and semisweet chocolates available to home cooks contained less than 60% cacao, and most recipes were developed accordingly.
Today, supermarkets and specialty shops offer semisweet and bittersweet chocolates that range from 54% to more than 70% cacao. The choice is exciting, but chocolates with radically different cacao percentages can produce radically different results. Substituting chocolate with significantly higher cacao (70% instead of 54% or even 60%, for example) has an effect similar to subtracting sugar and replacing it with unsweetened cocoa powder. Cakes will be dry and crumbly and might taste bitter, mousses will have a grainy texture, and ganaches and sauces will almost certainly curdle.
Since I love the flavor and complexity of modern high-cacao chocolates, I often create recipes specifically for them. To ensure success for the home cook, I always specify chocolates with the cacao percentage (or range of percentages) that will result in the right balance of flavor, texture, and sweetness.

Q.Why use chocolates with different percentages in the same dessert?

A.I love using a variety of chocolate elements in the same dessert—not just chocolates with different cacao percentages but also cocoa powder or ground chocolate—because it allows me to create contrasts in sweetness, flavor intensity, and texture.

A better way to melt chocolate

The goal of melting chocolate is to make it fluid and warm (or very warm, depending on the recipe) to the touch without overheating or scorching it.

While most recipes call for a double boiler (a bowl set over a pan of simmering water), I much prefer a wide, shallow skillet of water with a stainless-steel bowl of chocolate sitting directly in it. The open bath lets me see and adjust the water if it begins to boil or simmer too actively, whereas the water in a double boiler is usually out of sight and thus trickier to monitor. Just as chocolate in a double boiler will scorch if the cook is inattentive, chocolate in an open bath must also be watched carefully, stirred frequently, and removed from the bath when melted.