To remove mold from leather, first ensure that the leather itself is completely dry. Next, wipe the mold away from the leather's surface using a soft, damp cloth. Allow the leather to re-dry, then wash the leather thoroughly with either a leather soap or gentle agent, such as baby shampoo.
If the damp cloth proves insufficient in removing the mold from the leather's surface, try a soft-bristled brush. When cleaning leather, make sure to clean the entire surface, making sure that the color, luster and texture remain uniform. Before using any type of cleaner, even one specified for leather, do a spot-test, choosing a less visible patch of the leather product for the application to see how it performs. Whenever cleaning leather, first refer to manufacturer instructions to avoid incurring preventable damage.
Detergents of any kind should never be used when removing mold from leather, as they are far too powerful and abrasive. If the cloth, brush and chosen cleaner fail to remove the mold, it is better to consult a leather producer/restorer in the area rather than continuing to experiment on your own. Finally, once the mold is removed, store the leather product in a clean, dry area if possible, to avoid recurring mold. If manufacturer information approves, consider adding a mildew inhibitor to the surface as well.