When we arrived home I have scoured the internet in search of comprehensive references of this humble cooking pot, but have found surprisingly little. Therefore this technique for sealing a brand new chatti, which our guide told us of, may be a true internet exclusive! Although no doubt, you'll tell me differently!
Add the grated meat of one coconut to the pot and slowly heat the pan, turning the contents occasionally, until the coconut is fully brown. Then empty the pot and allow it to fully cool. You then have to fill the pot with cold water and slowly heat the liquid until its boiling - this will likely require the lid. At this point add a liberal dusting of cooking salt and slowly simmer the liquid for several hours. In total i boiled our pot for approximately 8 hours, during which the impurities inherent in the terracotta pot were drawn out and were evident on the exterior of the pot. Its now ready to use. Exclusive over!!
I find the terracotta chatti a delight to cook in, and find it much more sympathetic to temperature variations than a metal alternative which is easy to over heat.
