How Can I Save Overheated Chocolate?
First, you will want to cool the chocolate, as it is harder to save overheated chocolate that has been at a high temperature for a long time. To cool the chocolate, remove the bowl from the heat source, transfer the chocolate to a dry, cool bowl, and stir in a handful of solid chocolate chunks. Stir constantly and allow the solid chocolate to bring down the temperature of the melted chocolate.

If the chocolate remains thick or lumpy, try straining it through a sieve first. If this doesn’t solve the problem, add a spoonful of vegetable oil or melted vegetable shortening and stir thoroughly. You can also try adding some freshly melted chocolate with a few drops of soya liquid lecithin (an emulsifier, available at health food stores), or using a handheld immersion blender to smooth the chocolate. If none of these tricks helps your chocolate, save it for use in baking recipes and begin again with a fresh batch of chocolate.

If the white chocolate is on the brink of overheating, quickly throw some more white chocolate bits in and stir thoroughly, which will cool the mixture. If it has just begun to overheat and seize up, you may be able to loosen it with the addition of a little cocoa butter, vegetable oil, or shortening. If it has gone any further, there is nothing you can do.