Very odd indeed.:)

Use it a lot,no depressions,very smooth coating on finished product.
Cheers from here

Hi Rick
This is one of those things that make you go hummmm.:)
Something in my recipe is causing small pockets, not a problem for me but puzzling never the less.

Someone told me i could use cat litter instead of vermiculite and I tried it today. will let you know if it works.

Most cat litters are clay. Clay and concrete don't mix well.

Sue