Question

Why are cocoons are deeped into hot water

Answer 1

The cocoon are put into the hot water to kills the worms inside the cocoons and also loosens the hold of the gum sericin on the filaments. If worms are not killed, they will secrete a fluid that will dissolve all the silk. 

Answer 2

HEY!!

HERE I YOUR ANSWER

Cocoons are placed in boiling water to dissolve the adhesive that glues one strand of silk to the layers below. This allows a single silk strand to be unrolled from the cocoon (usually about 20 strands are unwound together and this fiber bundle is then spun into a thread that is plied and subsequently woven).