The caffeine content in black tea can vary depending on factors such as the type of tea leaves used, brewing time, and brewing temperature. On average, an 8-ounce (240 ml) cup of brewed black tea contains approximately 30 to 50 milligrams of caffeine.
However, these are general estimates, and the actual caffeine content can vary. Some factors that can influence caffeine content in black tea include:
1. Type of tea leaves: Different varieties of black tea may have varying caffeine levels.
2. Brewing method: The longer you steep black tea and the hotter the water temperature, the more caffeine it will extract.
3. Tea bag vs. loose leaf: Tea bags may contain smaller or broken tea leaves, which can release more caffeine compared to whole leaf tea.
4. Serving size: Larger cups or mugs will contain more caffeine compared to smaller servings.
Overall, while black tea typically contains less caffeine than coffee, it can still provide a moderate caffeine boost. If you're particularly sensitive to caffeine or want to reduce your intake, you can opt for decaffeinated black tea or consider brewing tea with shorter steeping times.