Pure Leaf black iced tea has more caffeine than rooibos (red bush) tea on both counts: 54mg per 18.5 oz bottle against 0mg per 8 oz cup, and about 3mg per fluid ounce against 0. The serving sizes differ, so the table below shows both ways of counting.
rooibos (red bush) tea vs Pure Leaf black iced tea: the numbers
| rooibos (red bush) tea | Pure Leaf black iced tea | |
|---|---|---|
| Caffeine per serving | 0mg per 8 oz cup | 54mg per 18.5 oz bottle |
| Caffeine per fl oz | 0.0mg | 2.9mg |
| Servings to reach 400mg (FDA context) | n/a (caffeine-free) | 7.4 |
Sources: rooibos (red bush) tea's figure is verified in our rooibos (red bush) tea caffeine guide against USDA / naturally caffeine-free herbal (source); Pure Leaf black iced tea's figure is verified in our Pure Leaf black iced tea guide against PepsiCo label data (source).
The concentration gap is the striking part: Pure Leaf black iced tea packs roughly 292 times the caffeine per ounce. Sipping speed matters at that density; a 18.5 oz bottle 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 Pure Leaf black iced 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
- Pure Leaf black iced tea: the full caffeine guide
- The verified caffeine database
FAQ
Does rooibos (red bush) tea or Pure Leaf black iced tea have more caffeine? Pure Leaf black iced tea: 54mg per 18.5 oz bottle versus 0mg per 8 oz cup for rooibos (red bush) tea.
Which is stronger per ounce? Pure Leaf black iced tea, at about 2.9mg 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.