Coral sand

Yes, it is still important to toast coral sand. The reason for toasting to a light brown like a perfectly done marshmallow is twofold:

1. Remove the moisture from the calcarb so the vinegar will penetrate more easily and thoroughly dissolve all the calcium out into solution
2. Coral is full of tiny bits of organic matter, so to cook them out so that the mixture will not rot later during storage.

I recommend doing this on a slightly higher heat that has been traditionally taught, around a low medium so that it will take about 15 minutes with constant stirring as not to burn. Try not to burn the coral and turn it black as that chemically destroys the calcium and starts to carbonize it. Sort of like the marshmallow, it takes keen effort and the right heat to cook it just perfectly!

Good luck, and Long live the natural farmer!