Handpicking

Malli and his sister Valli are touring India in their summer holidays. First stop: their Nani's house in Haryana, surrounded by large fields. In the courtyard, their Mami, Mama and others from the community are picking small stones and husk out of piles of grain with their hands. Nani explains: the stones must be removed so that the grains are fit for cooking.

A mixture is two or more substances mixed together. Picking out the unwanted particles of a mixture by hand is called handpicking. We can pick stones and husk out of wheat and rice because they look different from the grains. Handpicking works on differences in size, colour and shape: you have to be able to see what you are picking out.

At lunch Malli gets hot vegetable pulao. He picks out the whole black peppers and puts them aside on his plate. Valli laughs: "That's handpicking!" The peppers are easy to see, and there are only a few.

When does it work? Handpicking is convenient only when the particles to be removed are few and easy to pick by hand. It costs nothing but your time. With a huge amount to remove, or particles that look just like the rest, picking them out one by one would take far too long.