Published November 1, 2010. From Cook's Illustrated.
With no added sugar or dairy, 100 percent pure chocolate can be a clear route to rich chocolate flavor—or bitter proof that not all bars are created equal.
For most of the 20th century, unsweetened chocolate played a starring role in the home baker’s pantry. Today, however, it seems upstaged by bittersweet or semisweet chocolate, showing up in fewer recipes. But in the test kitchen, we often rely on unsweetened chocolate as a building block in desserts such as brownies and chocolate cake; it’s an excellent way to deepen chocolate flavor without adding sweetness.
The purest form of chocolate, with no sugar or other ingredients added, unsweetened chocolate is definitely not candy (as anyone who’s sampled it plain can tell you). Mayans mixed it with hot water and drank it as a bitter, stimulating beverage, the way we drink black coffee. Spanish explorers brought it home, and within the next century it was all the rage in Europe (though often with added sugar and milk). But for all its popularity, chocolate remained a luxury until the Industrial Revolution, when mass production made it cheap enough for mass consumption. One of the first food manufacturers in America was the James Baker Co. of Dorchester, Mass., which began making Baker’s brand unsweetened chocolate in 1765. Milton Hershey’s first chocolate was an unsweetened baking bar introduced in 1894 (the famous milk chocolate bar followed six years later).
Both of those pioneering American products are still sold in supermarkets. But like other forms of chocolate, the unsweetened kind has gone upscale these days, and basic brands share the shelves with far more expensive products billing themselves as “premium” or “artisan.” There are also myriad fancy unsweetened chocolates available through mail order. Could any of these top the originals? We rounded up seven other competing brands and baked all nine in classic brownies and then mixed them into chocolate sauce to find out.
We asked our tasters to rate the samples on the intensity and complexity of chocolate flavor—and right from the start it was clear that unsweetened chocolates are not all alike. From nutty to fruity, smoky, and coffeelike flavors, they brought a wide range of nuances to our tasting table. Since most of these chocolates contain nothing more than processed cacao beans, we could only assume that any flavor complexities derived from the beans themselves, which manufacturers roast and blend to further manipulate their product’s typical flavor profile.
When we tasted the brownies, though, we were surprised that some of the more exotic chocolates actually fell short. Tasters described brownies as “bland, not much in the way of complexity,” “mild,” and “nothing special.” Their comments on others echoed these sentiments: “pretty meek,” “dull,” and “one-dimensional.” Another chocolate fared no better, with tasters complaining, “Where’s the chocolate?”
The best-liked brownies came from three sources: a French brand that tasters praised for a “smoky” profile; another which was noted for being very sweet, with “raisin,” “raspberry,” and “coffee undertones”; and to our surprise, one of the everyday supermarket brands. Tasters raved about its “well-rounded, complex flavors,” including suggestions of “caramel and coffee,” with “rich, deep, bittersweet notes” and “big” chocolate flavor. However, our other classic American brand didn’t fare nearly as well. Some tasters liked the cherry tones this chocolate provided, but most found it underwhelming, tasting far more of sugar than of chocolate.
Intrigued but not yet convinced, we sampled all the entries again, this time in a simple chocolate sauce. The tasters’ scores and comments mirrored the brownie results almost exactly.
Chocolate manufacturers closely guard their trade secrets, so discovering exactly what made the top-ranked chocolate brands stand out was not easy. We sent the chocolates to an independent laboratory to analyze their percentages of cocoa solids and cocoa butter—the two components that make up cacao beans. We also compared ingredient lists and evaluated tasters’ comments for clues.
While every unsweetened chocolate is made up of 100 percent cacao or very close to it (some brands contain trace amounts of other ingredients such as vanilla or lecithin), we found the chocolates varied in the amount of cocoa butter they contain. According to federal regulations, unsweetened chocolate must contain no less than 50 percent and no more than 60 percent cocoa butter. Our lab tests revealed that our winner had the lowest fat level of all of the chocolates, with just 50.3 percent. Most of the rest of the lineup contained between 52 and 55 percent fat, a typical amount that naturally occurs in cacao beans. With the least cocoa butter, the test kitchen favorite contains more cocoa solids than the rest of the lineup, which would explain its richer chocolate flavor.
But so far, all we had was a partial explanation, because some of the lowest-ranked chocolates also contained high levels of cocoa solids. So merely having more chocolate flavor isn’t enough: It has to be good chocolate flavor. Over-roasting may have been the downfall of a bottom-ranked brand: Tasters noticed burned flavors, “like licking charred bark,” “smoky,” and “unpleasant.” Baker’s shared that “burnt,” “earthy, soil-like” profile.
And then there are the beans themselves. Given that unsweetened chocolate is simply roasted ground cacao beans, usually not refined or conched (a process of grinding chocolate particles very finely while aerating the chocolate and mellowing the flavor), there’s no hiding mediocre beans and faulty roasting. But experts told us that the best beans generally are not used in unsweetened chocolate. “Since it is also called baking chocolate, and used in recipes with other ingredients, not usually eaten alone, you often find a wider variation in its quality,” said Gregory Ziegler, a professor of food science at Penn State University. “I’d think that these products would typically be a blend of average beans.” But our winner’s ingredient label also shows that it contains added cocoa (more cocoa solids with some fat), and one expert speculated that the company incorporates higher-quality cocoa into a base of cheaper beans to boost the flavor.
When all is said and done, do we still recommend using unsweetened chocolate? Yes. When we developed our recipe for Old-Fashioned Chocolate Layer Cake (March/April 2006), only unsweetened chocolate created the traditional tender, airy, open crumb that stood tall, not fudgy and dense like more modern cakes. We’ll also continue to use it as a way to pack more chocolate flavor into chocolate desserts while keeping the sweetness under control. Because overall scores in this testing were close for most of the top of the lineup, any of the higher-ranked unsweetened chocolates will do the job. Just avoid the bottom-ranked brands—they’ll only add weak chocolate flavor and possibly some unpleasant off-flavors, too.