Starbucks cold brew (grande) has more caffeine than rooibos (red bush) tea on both counts: 205mg per 16 oz grande against 0mg per 8 oz cup, and about 13mg per fluid ounce against 0. The serving sizes differ, so the table below shows both ways of counting.
These are different categories of drink, which changes how the caffeine arrives. Energy drinks and sodas list an exact number because caffeine is a measured additive; brewed drinks vary with the beans and the brew, so their figures are compiled averages. The numbers here are the standard published values for each.
rooibos (red bush) tea vs Starbucks cold brew (grande): the numbers
| rooibos (red bush) tea | Starbucks cold brew (grande) | |
|---|---|---|
| Caffeine per serving | 0mg per 8 oz cup | 205mg per 16 oz grande |
| Caffeine per fl oz | 0.0mg | 12.8mg |
| Servings to reach 400mg (FDA context) | n/a (caffeine-free) | 2.0 |
Sources: rooibos (red bush) tea's figure is verified in our rooibos (red bush) tea caffeine guide against USDA / naturally caffeine-free herbal (source); Starbucks cold brew (grande)'s figure is verified in our Starbucks cold brew (grande) guide against Starbucks menu data (source).
The concentration gap is the striking part: Starbucks cold brew (grande) packs roughly 1281 times the caffeine per ounce. Sipping speed matters at that density; a 16 oz grande 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 Starbucks cold brew (grande) 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
- Starbucks cold brew (grande): the full caffeine guide
- The verified caffeine database
- Every drink compared: the comparisons index
FAQ
Does rooibos (red bush) tea or Starbucks cold brew (grande) have more caffeine? Starbucks cold brew (grande): 205mg per 16 oz grande versus 0mg per 8 oz cup for rooibos (red bush) tea.
Which is stronger per ounce? Starbucks cold brew (grande), at about 12.8mg 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.