brewed black tea has more caffeine than rooibos (red bush) tea: 47mg vs 0mg in the same 8 oz cup. That is a 47mg gap, and since the cans match, the per-serving number is the whole story.
rooibos (red bush) tea vs brewed black tea: the numbers
| rooibos (red bush) tea | brewed black tea | |
|---|---|---|
| Caffeine per serving | 0mg per 8 oz cup | 47mg per 8 oz cup |
| Caffeine per fl oz | 0.0mg | 5.9mg |
| Servings to reach 400mg (FDA context) | n/a (caffeine-free) | 8.5 |
Sources: rooibos (red bush) tea's figure is verified in our rooibos (red bush) tea caffeine guide against USDA / naturally caffeine-free herbal (source); brewed black tea's figure is verified in our brewed black tea guide against USDA FoodData Central (source).
The concentration gap is the striking part: brewed black tea packs roughly 588 times the caffeine per ounce. Sipping speed matters at that density; a 8 oz cup finished in minutes hits differently than the same milligrams spread over a slow cup.
Which one should you pick?
Pick rooibos (red bush) tea when you want the lighter dose or a slower ramp, and brewed black tea when you actually need the bigger hit and know your tolerance. If you are stacking either with other caffeinated drinks through the day, run the math against the 400mg reference rather than guessing.
For context, the FDA cites 400mg of caffeine a day as an amount generally not associated with negative effects in healthy adults. Tolerance and health vary, so treat these numbers as information, not advice.
Related reading
- rooibos (red bush) tea: the full caffeine guide
- brewed black tea: the full caffeine guide
- The verified caffeine database
- Every drink compared: the comparisons index
FAQ
Does rooibos (red bush) tea or brewed black tea have more caffeine? brewed black tea: 47mg per 8 oz cup versus 0mg per 8 oz cup for rooibos (red bush) tea.
Which is stronger per ounce? brewed black tea, at about 5.9mg per fluid ounce versus 0.0mg for rooibos (red bush) tea.
Comparing caffeine? The caffeine comparison tool puts hundreds of drinks side by side, and the caffeine curfew calculator can check your cutoff time for tonight.