The best grind size for Vietnamese phin coffee is medium-fine: finer than cafetiere coffee, usually coarser than espresso, and adjusted by drip speed. If your phin runs through quickly, the grind is probably too coarse. If it barely drips, the grind is probably too fine or the insert is pressing too hard.
Do not chase one universal grinder number. Different grinders use different scales. Use the cup and the drip as your guide.
Grind Size By Brewer
| Brew method | Typical grind | Compared with phin |
|---|---|---|
| Cafetiere | Coarse | Usually too coarse |
| Pour-over | Medium | Sometimes close |
| Phin | Medium-fine | Target range |
| Espresso | Fine | Often too fine |
What A Good Drip Looks Like
After the bloom, the phin should begin with slow drops, then settle into a steady drip. It should not pour like a tap and it should not sit motionless for several minutes.
If you see a fast stream, grind finer or use a little more coffee. If nothing happens, grind coarser, reduce insert pressure and rinse the holes.
Burr Grinder Settings
With a burr grinder, start near the finer end of filter coffee. Move one or two clicks at a time. Keep coffee dose and water amount the same while testing. If you change grind, dose and water all at once, you will not know what fixed the cup.
For dose guidance, use how much coffee for a Vietnamese phin.
Pre-Ground Coffee
Pre-ground Vietnamese coffee can be convenient, especially if the bag says it suits phin brewing. Regular supermarket coffee may work, but it can be unpredictable. Espresso-ground coffee is often too fine. Cafetiere-ground coffee is often too coarse.
Read can you use regular ground coffee in a phin filter for a more detailed answer.
Taste Troubleshooting
| Result | Likely grind issue | Adjustment |
|---|---|---|
| Weak and thin | Too coarse | Finer |
| Sour or hollow | Too coarse or too fast | Finer or more coffee |
| Bitter and muddy | Too fine or stalled | Coarser |
| No drip | Too fine or too much pressure | Coarser and lighter insert |
Conclusion
Medium-fine is the right starting point, but the best phin grind is the one that gives a steady drip and balanced flavour. Change slowly, keep notes and let the filter teach you its range.
Frequently asked questions
What grind size is best for a Vietnamese phin?
Start medium-fine: finer than cafetiere coffee but usually coarser than espresso. Adjust according to drip speed and taste.
Can espresso grind be used in a phin?
It is usually too fine and may clog the filter, especially with a tight insert.
Can supermarket ground coffee work in a phin?
It can work if it is not too coarse or too fine, but results vary. A burr grinder gives more control.
How do I know the grind is wrong?
If the phin races through, grind finer. If it stalls or tastes muddy, grind coarser.