(MONEY Magazine) – Delicious for nibbling, invaluable for developing your palate--and irreplaceable in the kitchen. Once you start baking with the best, there's no going back.

SINGLE-ORIGIN ASSORTMENTS The easiest way to taste regional differences is Le Nuancier des Pures Origines du Monde, from Michel Cluizel, a company famous for purity of flavor. Thin disks of high-percentage chocolate from seven regions are arranged in the presentation box from the most delicate (Grenada) to the most robust (Java); $31.57; echocolates.com; 800-207-7058.

For something richer, try the Tamanaco assortment from La Maison du Chocolat, which deserves its reputation for quiet, authoritative luxe. These chocolate-covered, ganache-filled tablets, made from beans of five different origins, are close to perfection; $59; www.lamaisonduchocolat.com; 877-740-5632.

BLENDED BARS Most of the bars in MONEY's tasting were bought through chocosphere.com, an excellent source for top-quality plain chocolates. Worthy brands include Côte d'Or, El Rey, Green & Black's and Scharffen Berger. Other fine names: Michel Cluizel, whose Amer 72% bars ($4.95 for 3.5 ounces) came out third in the tasting; Valrhona, whose Caraïbe bars ($3.50 for 2.62 ounces) were second; and Dagoba, maker of the organic New Moon bars ($2.75 for two ounces) that finished on top.

When organic chocolates first appeared in the late '80s, the only thing they had in common with luxury chocolate was price. The only people who bought them were the environmental avant-garde. Now organic chocolates can compete with the best in the business. Environmental awareness is mainstream, and so is "fair trade"--the idea that growers should share in profits when world prices rise. Chocolate is mostly grown by small farmers who do not enjoy this benefit. A few of these farmers are very small indeed--children as young as nine. And especially in West Africa, where 70% of cacao is grown, market forces strongly favor unsustainable farming methods.

While exact numbers on these issues are hard to come by (and hotly debated), few chocolate lovers are keen to make them any larger. Partly as a result, the organic and fair-trade category is growing at 10% to 15% a year, according to the World Cocoa Foundation, a nonprofit offshoot of the Chocolate Manufacturers Association. And since consumption is outpacing production by 5% or more a year, the looming shortage of beans has made even hard-nosed industrial buyers increasingly farmer-friendly and ecologically aware. --L.L.