Troubleshooting Truffles
If your ganache is broken, gently warm the ganache in the microwave or over a water bath. The goal is tho get it warm and fluid, not hot, so microwave at 10-second intervals or keep it on the water bath for 30-second intervals at a time, and whick between each heating sessiong until it reaches about 100 F. Often, reheating is enough, but if this does not work, add a teaspoon of room temperature milk and continue whisking until it comes together.
The chocolate coating on your dipped truffles has cracked. Many recipes suggest letting the formed tuffles sit overnight in a cool room before dipping them. This overnight curing period allows the ganache to become firm and dry, which makes it easier to dip them at room temperature. Dipping cold truffles in chocolate often causes the chocolate to crack. This is why dipping at room temperatures is ideal.
If you put the truffles in the refrigerature to chill the truffles just until firm, your chocolate could crack. One option is to redip inn chocolate once the truffles are at room temperature.