I confess that I do not know what a socarrat is so I looked at Wikipedia. The answer is.
Socarrat refers to fired
clay tiles covered with a white base and generally painted in red and black. These were placed between
beams and
joists in buildings’ ceilings and
eaves. Their origin is typically medieval but subsequent production of these objects is known, mainly in
Valencia. There are other words to name objects with similar function such as rajola, maó prim, atovó or cairó. The first register about its existence takes us back to 1604, when D. Feliciano de Figueroa, Bishop of
Segorbe, refers to a group of roof and wall
tiles written and coloured with koranic transcripts. Traditionally, they’re said to come from
Paterna but the presence of these and other similar objects has been documented too in
Manises and in some other places in
Valencia,
Aragon and
Catalonia.
[1]
I sure hope you weren't planning to build with this stuff. Then I looked further.
Socarrat can also refer to the crust that forms on the bottom of the pan when cooking
paella.