To make the tea stronger, don’t steep it for longer —unless it’s herbal. Steeping a tea for too long will make it bitter rather than strong. Instead, add more tea leaves.
As a general rule, use one level teaspoon or 2 grams for every cup (8 oz) you’re making.
Fluffier ingredients like mint and chamomile or teas with larger leaves like green tea or oolong could use an extra teaspoon.
Many teas such as oolong, green tea, white tea, and pu-erh are good for a second and sometimes third steeping.
Pu’er teas: 200° to 212°F (93°to 100°C)
Black teas:190° to 200° Fahrenheit (88° to 93°C)
Oolong teas: 180° to 200°F (82°to 93°C)
Yellow teas: 175°F (79°C)
White teas: 160° to 185°F (71° to 85°C)
Green teas:140° to 190° F (60° to 88° C)