Why does Crusoe need pots?

Crusoe wants earthenware pots to cook in the fire. As for how he learns to make them, the text reads as follows.....

"I had no notion of a kiln, such as the potters burn in, or of glazing

them with lead, though I had some lead to do it with; but I placed three

large pigskins, and two or three pots in a pile, one upon another, and placed

my firewood all round it, with a great heap of embers under them. I plied

the fire with fresh fuel round the outside, and upon the top, till I saw the

pots in the inside re-hot quite through, and observed that they did not crack

at all. When I saw them clear red, I let them stand in that heat about five or

six hours, till I found one of them, though it did not crack, did melt or run,

for the sand which was mixed with the clay melted by the violence of the

heat, and would have run into glass, if I had gone on; so I slacked my fire

gradually till the pots began to abate of the red color; and watching them all

night, that I might not let the fire abate too fast, in the morning I had three

very good, I will not say handsome, pigskins, and two other earthen pots, as

hard burnt as could be desired, and one of them perfectly glazed with the

running of the sand."