Heat cold tap water in a kettle. Bring it to 160 to 180 degrees Fahrenheit, which is hot enough to steam but not boil. Boiling water loses oxygen, which affects the flavor of the tea, and the hotter temperatures can also ruin the flavor of green tea.

Place 2 tablespoons of loose leaves in the teapot for every three teacups of water, or use one tea bag per 8 ounces. Use a self-straining teapot or place the leaves in a large infuser ball then place them in the teapot. The amount of tea should fill an infuser no more than half full.

Pour the hot water over the tea in the pot. Place the lid on the teapot and allow the sencha to steep for about 90 seconds. Brewing too long or at an overly high temperature causes bitterness to develop in the sencha.

Rinse your teacups in hot water before pouring. This preheats them so the tea doesn't cool too quickly after you pour. Pour the tea into the teacups. Fill each cup halfway on the first pass, then finish filling them in the same order initially used. This ensures each cup receives some of the stronger tea from the bottom of the pot, and provides uniformity of flavor and color in each cup.