Use 20 to 25 grams of medium ground coffee, bloom with 25 to 30 ml of water at 90 to 96 degrees Celsius, wait 30 to 45 seconds, then fill the phin and let it drip for 4 to 6 minutes. That produces a short, strong cup built for condensed milk and ice. Below is the full method, the numbers behind it, and what to change when the cup is wrong.

What you need

• A phin filter, 20 to 25 g size. See how to choose a phin.
• Coffee ground to a medium grind, close to table sugar in texture.
• Water at 90 to 96 degrees Celsius, ideally 92 to 94.
• A scale and a timer. Both optional, both make the cup repeatable.

Step by step

Step	What to do	Why it matters
1. Rinse	Pour hot water through the empty phin and cup, then discard	A cold phin steals heat and the cup turns sour
2. Dose	Add 20 to 25 g of ground coffee, tap gently to level it	An uneven bed makes water run down one side
3. Fit the lid	Screw the gravity insert down until it just grips, no harder	Over-tightening chokes the flow and makes it bitter
4. Bloom	Pour 25 to 30 ml in circles, wait 30 to 45 seconds	Lets trapped gas escape so water can wet the bed evenly
5. Fill	Add the rest of the water and cover the phin	The lid keeps temperature stable through the drip
6. Wait	Let it drip for 4 to 6 minutes, then lift the phin off	The last slow drops carry mostly harsh, drying flavours

Ratios by the cup you want

Cup	Coffee	Total water	Ratio
Iced milk coffee, ca phe sua da	22 to 25 g	85 to 95 ml	about 1:3.5
Black iced coffee, ca phe da	20 to 22 g	120 to 160 ml	about 1:6
Black hot, sipping	18 to 20 g	140 to 160 ml	about 1:8

These are far stronger than the 1:15 to 1:18 the SCA suggests for paper filter brewing. That is deliberate: a phin cup is built to survive condensed milk and melting ice. Pour western filter ratios into a phin and the result tastes thin.

Fixing a cup that came out wrong

Problem	Usual cause	Change this first
Sour and thin	Water ran through too fast, or was too cool	Grind one step finer, raise the water to 94
Bitter and drying	Over-extraction, or a very dark roast	Grind coarser, loosen the insert, lift the phin sooner
Watery	Too little coffee for the phin size	Add 2 g, or use a smaller phin
Nothing drips	Ground too fine, insert screwed down hard, or clogged mesh	Loosen first, then grind coarser, then clean the phin

Each of these has a longer article behind it: grind size for phin, water temperature, drip speed problems and bitterness. They are written in Vietnamese, but the tables and numbers read across languages.

Which coffee to use

Traditional phin uses Robusta roasted medium dark to dark: heavy body, low acidity, strong enough for condensed milk. A cleaner, fruitier cup comes from Fine Robusta or from Arabica roasted medium, which is what specialty phin brewing has moved toward. Whichever you choose, buy whole beans with a roast date and grind before brewing.

Want to try all of them side by side with a trainer? See the Vietnamese phin coffee class in Mang Den.

More on Vietnamese phin coffee

Our English guides to the phin, written by trainers at a coffee lab inside a Vietnamese growing region.

• What is a Vietnamese phin
• Ca phe sua da, Vietnamese iced coffee
• Vietnamese phin coffee class in Mang Den, learn it hands-on at the farm (see the fee and book)
• PHIN VIET Foundation, the one-day course

Frequently asked questions

How long should a phin take to drip?

Four to six minutes for a single serve phin. Under three minutes means the grind is too coarse; over eight minutes means it is too fine or the insert is too tight.

Should I press the coffee down hard?

No. A phin is not an espresso basket. Screw the insert down until you feel resistance and stop there.

Can I use a paper filter coffee in a phin?

You can, but a filter grind is usually too coarse and the cup will be thin. Grind finer, closer to table sugar.

Sources

• Specialty Coffee Association, brewing ratios and water temperature guidance, sca.coffee
• Vietnamese Phin Brewing Standard, compiled by Stone Village Coffee Lab, see the course page