Usucha & Koicha are two traditional Japanese styles of Ceremonial Matcha preparation. Usucha is literally light tea, thinner type of Matcha Tea, while Koicha is thick tea.
Koicha, the thick stronge dense tea is preferably made with higher grades of Matcha, by which we get more vibrant color, natural sweetness and long lasting umami taste. Matcha used in Koicha is from leaves of first harvest of plants that are minimum 30 years old, like Pristine Leaf Premium Ceremonial Oragnic Japanese Matcha and Pristine Leaf Ceremonial Organic Matcha [Link]. Since Koicha is thick tea, use of lower grade of Matcha, like Culinary Matcha will make it taste extremely unpleasant.
On the other hand, Usucha, thin tea, is typically made from leaves of tea plants that are less than 30 years old. It can be prepared with any grade of Matcha, though the flavor of tea depends on grade of Matcha used in its preparation. However, in general, when talking about Tea Ceremony, people refer to Usucha which made with higher Premium Ceremonial & Ceremonial grade Matcha.
Quantity of Matcha & method of preparation of Koicha and Usucha is different. Generally for Koicha, as much as 4g (0.14oz) about 3 teaspoons of Matcha is used, & Usucha requires 1/4 quantity of Matcha than Koicha, about one-two grams (1 teaspoons) of servings of Matcha.
Amount of water used in Koicha is very less than Usucha, about one fl. ounce (30 ml / 2 tablespoons) of water and Usucha uses 3 to 4 fl. ounces (120 ml/ 8 tablespoons) of water.
Preparation method for both are bit different. Usucha has nice layer of crema/ bubbles which typically achieved using Japanese traditional bamboo whisk in M or W whisk motion. Don’t be afraid to make it modern way using PL electric whisk/milk frother. You can purchase good quality tested in PL Kitchen, PL brand traditional Japanese Bamboo whisk as well as modern hand-held PL electric milk frother here at Pristine Leaf. [Link]
Unlike Usucha, Koicha has not crema at all. One massages/kneeds large quantity of tea & few drops of water with a whisk, gradually adding tiny bit of rest of water which reheats the tea and makes it more viscous. The final viscosity of Koicha is similar to melted chocolate, whereas Usucha is more like a macchiato.
In traditional formal Tea Ceremony, a bowl of Koicha is shared among several guests, drunk from the same cup by taking turns. Since Koicha uses higher grade of Matcha and, it was more of lavish expensive affair. As Tea Ceremony spread among public, people preferred & started using affordable Matcha, and it is believed to be reason Usucha becoming the norm in currently practiced Tea Ceremonies.
Pristine Leaf Premium Ceremonial Matcha is high grade Matcha sourced from family own tea farm on foothills of Kyoto, Japan with history of making tea for over 200 years. Organically shade grown, handpicked first harvest of spring, traditionally stone grounded in batches and packed with freshness, subtle aroma and umami taste. Pristine Leaf Premium Ceremonial Matcha makes great Koicha as well as Usucha.