I recently purchased Mayordomo puro chocolate in Oaxaca, thinking to bake with it. Most recipes that include Mexican chocolate seem to refer to the kind for making hot chocolate--containing sugar, nuts and either cinnamon or vanilla, but this is unsweetened, with cacao beans listed as the only ingredient. No cocoa butter, no sugar. Nada. Question: I made Mark Bittmans' tofu chocolate dessert, adding a portion of sugar to the melted chocolate to replicate the proportion of sugar (4 oz to 8 oz chocolate) in good Scharffenburger bittersweet (what I thought he was using). It was good....but very different. And when I left a silver spoon in the ramekin of chocolate pudding it turned black! Is this chocolate acid?? Should I correct the acidity with something like baking soda? Is cocoa powder treated with alkali for this reason? Suggestions are welcome.