It is not dyed green, but produced from young rice kernels roasted over very low heat then pounded in a mortar and pestle until flattened.

It is a popular seasonal dessert across Vietnam, especially in Red River Delta cuisine.

It is traditionally produced at the Cốm Vòng village in Hanoi.

Cốm is often offered to worship ancestors during the Mid-Autumn Festival.

It can also be used to make a dessert rice pudding called chè cốm.