Ratio and temperature
Sift 4 grams of matcha into a warm chawan and add 30 to 40 milliliters of water at around 70 degrees Celsius. Koicha uses roughly twice the powder and half the water of usucha, so only top tier matcha can carry the concentration without turning bitter.
Kneading the tea
Move the chasen slowly through the powder in a folding motion rather than whisking quickly. The goal is a smooth, glossy paste with no foam, often described as paint-like. Total kneading time is about 30 seconds.
When to drink koicha
Koicha is intense and concentrated, so it is usually shared in small sips rather than as a full bowl. Use only matcha labeled by the producer as suitable for koicha, such as the higher tiers from Ippodo or Marukyu Koyamaen.