My guess was that it may be ground bone, but I'm not sure and hadn't a clue what to do with it if it was. Assuming it's unvarnished, wash with soapy water and dry thoroughly. Wipe with pharmacy-grade mineral oil. Repeat these two steps after each use. Some will tell you to use cooking oil, but it tends to get tacky and rancid-smelling over time.
Any ideas welcome.
I believe there is something that can be added to the remaining soup to help reduce the amount of salt content, but I cannot remember what that ingredient was. I followed the recipe to the letter. I am a culinary student currently in a Garde-Manger II course with a research assignment. The problem is lack of access to a library. I believe there is something that can be added to the remaining soup to help reduce the amount of salt content, but I cannot remember what that ingredient was.