brewed oolong tea has more caffeine than rooibos (red bush) tea: 37mg vs 0mg in the same 8 oz cup. That is a 37mg gap, and since the cans match, the per-serving number is the whole story.
brewed oolong tea vs rooibos (red bush) tea: the numbers
| brewed oolong tea | rooibos (red bush) tea | |
|---|---|---|
| Caffeine per serving | 37mg per 8 oz cup | 0mg per 8 oz cup |
| Caffeine per fl oz | 4.6mg | 0.0mg |
| Servings to reach 400mg (FDA context) | 10.8 | n/a (caffeine-free) |
Sources: brewed oolong tea's figure is verified in our brewed oolong tea caffeine guide against USDA FoodData Central (source); rooibos (red bush) tea's figure is verified in our rooibos (red bush) tea guide against USDA / naturally caffeine-free herbal (source).
The concentration gap is the striking part: brewed oolong tea packs roughly 462 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 oolong 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
- brewed oolong tea: the full caffeine guide
- rooibos (red bush) tea: the full caffeine guide
- The verified caffeine database
- Every drink compared: the comparisons index
FAQ
Does brewed oolong tea or rooibos (red bush) tea have more caffeine? brewed oolong tea: 37mg per 8 oz cup versus 0mg per 8 oz cup for rooibos (red bush) tea.
Which is stronger per ounce? brewed oolong tea, at about 4.6mg 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.