Koicha: How to Prepare Thick Matcha Green Tea

Koicha matcha is a highly concentrated preparation of matcha tea, with just a small amount of water mixed into the tea powder. Since there are only two ingredients in koicha—matcha and water—it’s essential to use ceremonial-grade matcha, the highest quality tea grade available. Japanese tea culture has its roots in Kyoto, so a popular option is regionally harvested Uji matcha.

Matcha is the stone-ground form of tencha, a variety of green tea leaves. The tea is notable for its vibrant green color, grassy taste, and purported health benefits. Traditionally, producers grew matcha tea plants under the shade of bamboo mats (nylon fabric is now the standard). Blocking the tea bushes from sunlight increases the plant’s concentration of chlorophyll and theanine, resulting in the smooth, less bitter-tasting flavor that makes it so popular in wagashi (Japanese sweets) like mochi.

Koicha is a thick tea, while usucha is a thin tea. Both contain the same ingredients (ceremonial-grade matcha and water) but involve different tea-powder-to-water ratios. Koicha tea uses half the amount of water as matcha usucha tea, resulting in its concentrated flavor, color, and thickness.

Preparation methods start similarly, with the same amount of matcha—one teaspoon—and 175-degree-Fahrenheit water. For koicha, whisk one and a half ounces of water slowly into the chawan to avoid creating any bubbles. Slow whisking will yield a syrupy consistency comparable to runny honey. To prepare usucha, whisk two and a half ounces of water into the chawan to create a frothy, bubbly head and a more diluted tea.

Traditional Japanese tea ceremonies, or chanoyu, are a reverent celebration of tea and the quiet, contemplative enjoyment it inspires. Like most rituals, traditional tea preparation calls for a few tools: a chashaku, a chasen, and a chawan.

A bamboo scoop, or chashaku, doles out the correct portion of matcha tea. Each scoop is equivalent to half a teaspoon, so a measuring spoon works if you don’t have a chashaku. The bamboo whisk, or chasen, yields a smooth consistency, while a flat-bottomed tea bowl, or chawan, is just the right size and surface for whisking.

Koicha is ideal for seasoned matcha tea drinkers who want to experience high-quality matcha to its fullest. Those new to matcha will enjoy milder drinks like matcha cold brew and hot or iced matcha lattes, gradually building up to more concentrated variations. If you’re ready for koicha, here’s how to make it at home:

1. 1. Heat the water. Using a variable temperature kettle, heat the water to 175 degrees Fahrenheit. Alternatively, boil the water and let it cool for two minutes, checking the temperature with an instant-read thermometer if desired.
2. 2. Sift the matcha. Measure two chashaku scoops or one teaspoon of matcha and sift with a fine sieve into the chawan.
3. 3. Pour the water. Slowly pour one and a half ounces (40 milliliters) of heated water over the powdered matcha.
4. 4. Whisk the matcha. Hold the whisk with your dominant hand and the chawan with your other hand. Slowly and deliberately stir the fine powder and hot water together until the matcha is smooth and syrupy-looking, with no lumps or bubbles.

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