I use Spanish clay pots both in Spain and in the UK. We buy them from Cerámica Ramírez in the Barrio Nuevo in Conil. At one time they were sold from the back of a donkey from a vendor in the streets of the town. We still have one of his pots.
Before the first use or after long periods of non-use they must be “cured”. Curing involves soaking the pot in water for 12 hours. Traditionally the unglazed bottom of the pot is rubbed with a clove of garlic?? The pot is then filled with water and a small amount of vinegar, brought to the boil over a low heat and simmered until most of the liquid has evaporated. Some recommend rubbing the inside of the base with olive oil and baking in a hot oven for 2 hours.
Even cured pots can crack. I can think of several incidents where a “guiso” has leaked onto the hob as we were cooking; requiring an emergency transfer to another pot. You can see just such a crack in the photograph below!
