Salted duck eggs are wrapped in mud because they can easily produce oil, and it is better to wrap them in yellow mud. You can also soak it directly in salt water without mud.

Production of yellow mud: firstly, put salt and water into a jar or barrel, and after the salt is dissolved, pour the dried, mashed and screened loess into the jar and stir it with a stirrer to make it paste. The consistency of the stirred mud should be moderate. If it is too thick, the coating on the eggshell is uneven; On the contrary, it won't stick to the eggshell.

The method for checking the consistency of the mud is: take a fresh egg and put it into the mud. If half of the egg sinks into the mud and the other half is exposed on the mud surface, it means that the consistency of the prepared mud is appropriate.