Filter Coffee Decoction: Powder, Water and Milk Ratios

A good starting ratio for South Indian filter coffee is 2 heaped tablespoons of coffee powder (about 15 to 18 g) to 120 ml of water just off the boil, which makes enough decoction for 2 to 3 cups. In the cup, mix 1 part decoction with 3 parts hot milk, add sugar to taste, and adjust from there.

How much powder to water for the decoction?

A standard two-tier steel filter holds these amounts comfortably. If yours is larger, scale both powder and water up together.

How much decoction per cup of milk?

Start at 1 part decoction to 3 parts hot milk. For a 150 ml cup, that's about 35 to 40 ml of decoction and 110 ml of milk.

• Stronger: 1 part decoction to 2 parts milk
• Milder: 1 part decoction to 4 parts milk

Change one thing at a time. Coffee tastes weak? Try less milk before adding more powder.

How much sugar?

Usually 1 to 2 teaspoons per cup. Put the sugar in the tumbler first, so it dissolves as you pour the coffee back and forth.

Method

1. Put the powder in the upper chamber and level it. Set the plunger disc on top and press very lightly. Don't pack it down.
2. Pour water that's just off the boil over the plunger disc, filling to the right level for your ratio.
3. Cover and leave it to drip for 10 to 15 minutes.
4. Meanwhile, heat the milk until it just rises and turns frothy.
5. Add sugar, then decoction, then milk to the tumbler. Pour between the tumbler and davara a few times to mix and build froth.

Troubleshooting

• Drips too slowly (more than 20 minutes): powder too fine or pressed too hard. Press more lightly next time.
• Drips too fast and tastes weak: too little powder, or powder too coarse. Add a spoon more.
• Bitter: too much chicory in the blend, decoction left standing on heat, or reheated milk that's scalded. Make decoction fresh and warm the milk gently.
• Flat taste even at the right ratio: old powder. Use within a couple of weeks of opening.
• Too thin even when strong: milk ratio too high. Try 1 to 2 before changing the powder.

Can you make a second decoction?

Yes. Many homes pour a second round of hot water through the same powder for later cups. It's lighter and less aromatic, but perfectly fine for a milder coffee in the afternoon. Mixing first and second decoctions together is also common.

Keeping decoction

Decoction tastes best within a few hours. If you make it in the morning for the evening, keep it covered in the fridge and warm the milk, not the decoction, so it doesn't turn bitter.

Which coffee we use

Ratios only work with fresh powder, so see how to store coffee powder. Our Naadan filter coffee is Wayanad Robusta blended with chicory in the proportion typical of a hotel-style filter coffee, not straight Robusta. Our posts on coffee and chicory ratios and Robusta vs Arabica go into how each affects the cup.