Why coffee is roasted
Because green coffee does not taste or smell like coffee. Roasting is the step that creates almost everything you recognise as coffee.
Green coffee smells faintly of hay and grass. Brew it and you get something sour and vegetal. Nothing about it suggests what it is about to become.
Heat changes that. As the seed roasts, sugars and amino acids react and generate hundreds of new aromatic compounds. Trapped gas builds until the bean audibly cracks and expands. Its colour moves from pale green through yellow to brown.
Roasting does not reveal the flavour of coffee. It creates it.
Why roast level matters
A lighter roast keeps more of the acidity and the character of where the coffee grew. A darker roast trades some of that away for body, bitterness and the deep roasted aroma most South Indian filter drinkers expect. Neither is better. They are different intentions.
Sundaram roasts in the shop. For bulk orders, coffee is roasted after the order is placed.
Curious what this tastes like in the cup? See the coffees.