Veer watches his mother churn curd with a wooden madhani until lumps of white butter float to the…

Why

Hiral's idea is understandable — before churning no butter can be seen, and afterwards there are lumps of it, so it looks as if something new was made. But butter is the fat that was in the milk all along, spread through the curd as droplets too small to see. Churning keeps knocking those droplets into each other until they stick together into lumps big enough to see — and because fat is lighter than the watery part, the lumps float up and can be scooped off. What's left is buttermilk (chhaachh), which is why buttermilk is so much less creamy than curd. Nothing new was created; one mixture was split into two parts. Test: curd made from fat-free (skimmed) milk gives almost no butter however long it is churned — no fat in, no butter out. Veer is right: churning is a method of separation that pulls out the fat already present in the curd.