Remove the lid and preheat the glass with warm water. Add 12-15g of ground coffee. Slowly purify warm water at 90 °C (15-180 ml/person) in the French press. Mix the water and ground coffee with a stick to mix them fully. Put the lid inside and wait for 3 minutes before pressing the plunger. Time depends on how much coffee is ground. Slowly press the piston evenly. Please note that this step is crucial. Now you can pour coffee into a pre-heated cup and drink with sugar or milk if desired.