How do I make coffee for a group?

Making coffee one cup at a time for eight people means the first cup is cold before the last is poured. Batch brewing plus a thermal flask solves both the timing and the quality problem, which is exactly what cafés do.

What you'll need

• Large cafetière or filter machine
• Thermal flask
• Scales
• Kettle (optional)

Step by step

1. Work out the total volume and scale the ratio.About 60g of coffee per litre. For eight 200ml cups you need roughly 1.6 litres and about 96g of coffee.
2. Preheat the thermal flask with boiling water.Fill it, leave it two minutes, tip it out. A cold flask takes several degrees off the coffee immediately.
3. Grind slightly coarser for a large batch.Larger volumes extract a little more, so a marginally coarser grind avoids bitterness at scale.
4. Brew as a single batch rather than several small ones.Consistent, faster, and everyone gets the same coffee. Several small batches vary noticeably.
5. Decant into the flask immediately after brewing.Coffee left on grounds keeps extracting and turns bitter; coffee on a hot plate turns burnt. The flask stops both.
6. Set out milk, sugar and cups separately.Let people serve themselves. It removes the bottleneck entirely and you can stay in the room.
7. Offer decaf and a hot water jug.Hot water lets people dilute to their preferred strength, which handles the range of tastes without brewing twice.
8. Make more than you think.People have second cups. Leftover coffee in a flask keeps for hours, or chills into iced coffee.

Tips

• Cold brew is excellent for groups in warm weather. Make it the night before and serve it over ice with no equipment on the day.
• A cafetière of that size is heavy when full — decant in two goes rather than one precarious pour.
• If people take milk, warming it in a jug is much faster than steaming individual portions.

Common mistakes

• Leaving coffee on a warming plate — It cooks and develops a burnt stewed flavour within twenty minutes. A thermal flask holds it unchanged for hours.
• Leaving brewed coffee sitting on the grounds — Extraction continues and the coffee becomes bitter. Decant immediately after brewing.
• Brewing cup by cup for a group — The first cups are cold before the last is made, and you spend the whole time in the kitchen.

Questions people ask