If you are a regular customer of native chocolate, perhaps you have notice a mold-like spots or coating on surface of some chocolate you bought. They are not molds, they are either sugar bloom or fat blooms. Definitely a fat bloom in pure baking chocolate. The green spots or coating with rancid smell are molds.
Blooms may occur in two ways 1)fat bloom, cocoa butter rises to the surface and turns white as it crystallizes 2) sugar bloom, it is formed by the action of moisture on sugar ingredients.
Chocolate with blooms are perfectly safe for consumption. There are no changes in quality / flavor except for the bad-looking appearance. On the other hand, discard chocolate with real molds ( mostly green in color ) and rancid smell.
Diving deeper into the world of chocolate, the two terms that I said natural are becoming unacceptable. Yes, they can still be eaten but can never provide the best customer experience.
Cocoa butter plays an important role in flavor. Chocolate should be refined, homogenized and there should be enough butter to coat all the particles. When it blooms, the homogeneity is disrupted, parts of the particles won’t have enough butter coatings, so the mouthfeel will not be silky smooth.
Same explanation is true for sugar bloom. Re-crystallized sugar on surface feels gritty.
Fat bloom can be prevented by proper tempering and storage. Keeping it beyond its melting point causes bloom. Molding without tempering also causes bloom.
For sugar bloom. Prevention is done by preventing exposure with high humidity environment. Molded chocolate out from chiller may catch a lot of moisture if the room humidity is not maintained to acceptable level.
Marvin is the lead chocolate maker of Ben and Lyn Chocolate Inc. Has strong background in food research and development. Occasionally conducts training and lectures. Lecturer of Cocoa Foundation of the Philippines. Do coaching and consultancy services on his free time.