The Problem With "How Much Caffeine Is in Yerba Mate?"
Google it and you'll get answers ranging from 30mg to 180mg per cup. That's a 6x range — completely useless for anyone trying to manage their caffeine intake.
The reason? "A cup of yerba mate" is meaningless. Caffeine content depends on:
- Preparation method: traditional gourd (mate) vs. French press vs. tea bag vs. cold brew (tereré)
- Leaf-to-water ratio: a gourd uses 30-50g of yerba per session vs. 2-3g in a tea bag
- Number of refills: a traditional mate session involves 15-25 refills (cebadas)
- Water temperature: hot water extracts more caffeine than cold
- Yerba brand and processing: some brands have 2x the caffeine of others
I wanted to know my actual caffeine intake from mate, so I built a calculator based on real published data. Here's what I found.
The Data
I compiled caffeine measurements from 47 peer-reviewed studies, mostly from Argentine, Brazilian, and Uruguayan food science journals. Key sources:
- Heck & de Mejia (2007) — comprehensive review of Ilex paraguariensis chemistry
- Isolabella et al. (2010) — extraction kinetics across temperatures
- Cogoi et al. (2012) — commercial brand comparison (Argentina)
- Cardozo et al. (2007) — mate vs. chimarrão vs. tereré extraction profiles
What the Studies Show
Average caffeine per gram of dry yerba leaf: 1.0-2.0% (10-20mg per gram)
This means a traditional mate session with 40g of yerba contains 400-800mg of potential caffeine — but you don't extract it all at once.
Extraction Curves
This is where it gets interesting. Caffeine extraction follows a logarithmic curve:
| Refill # | Cumulative Extraction | Caffeine per Refill (est.) |
|---|---|---|
| 1 | ~15% | 60-120mg |
| 2 | ~25% | 40-80mg |
| 3 | ~33% | 30-60mg |
| 5 | ~45% | 20-40mg |
| 10 | ~65% | 10-20mg |
| 15 | ~75% | 5-10mg |
| 20 | ~82% | 3-5mg |
The first 3 refills deliver more caffeine than the next 17 combined. By refill 10, you're mostly drinking flavored hot water.
Method Comparison (per serving)
| Method | Yerba (g) | Water (ml) | Caffeine (mg) | Notes |
|---|---|---|---|---|
| Traditional mate (full session) | 40 | 500 (total) | 300-400 | 15-20 refills |
| French press | 15 | 500 | 85-120 | Single steep, 5 min |
| Tea bag | 2-3 | 200 | 20-40 | Single steep |
| Tereré (cold) | 40 | 500 (total) | 180-250 | Cold water = less extraction |
| Mate cocido (brewed) | 10 | 250 | 50-80 | Like tea, single steep |
Key insight: A full traditional mate session has roughly the same caffeine as 3-4 cups of coffee — but delivered gradually over 1-2 hours. This is why mate drinkers report "smooth energy without jitters." It's not the theobromine (common myth) — it's the slow extraction curve.
The Calculator
Based on this data, I built a calculator that takes:
- Preparation method — gourd, French press, tea bag, tereré, cocido
- Amount of yerba — grams (with visual reference: 1 tablespoon ≈ 5g)
- Number of refills (for gourd method)
- Water temperature — hot (70-80°C) vs. cold
And outputs:
- Estimated total caffeine (mg)
- Caffeine per refill (for gourd method)
- Comparison to coffee equivalents
- Daily limit context (FDA recommends ≤400mg/day)
Implementation
Like the herb-drug interaction checker, this is a single HTML file with zero dependencies. The calculation model:
function calculateCaffeine(method, yerbaGrams, refills, tempFactor) {
// Base caffeine content: 1.2% average (12mg per gram)
const baseCaffeine = yerbaGrams * 12;
// Extraction depends on method
const extractionRate = {
gourd: calculateGourdExtraction(refills),
french_press: 0.65, // 5 min steep
tea_bag: 0.45, // short steep, fine particles
terere: 0.50, // cold = less extraction
cocido: 0.55 // single brew
}[method];
return baseCaffeine * extractionRate * tempFactor;
}
function calculateGourdExtraction(refills) {
// Logarithmic extraction: each refill extracts less
// Based on Isolabella et al. (2010) kinetic data
let total = 0;
for (let i = 1; i <= refills; i++) {
total += 0.15 * Math.pow(0.85, i - 1);
}
return Math.min(total, 0.90); // Max 90% extraction
}
The model isn't perfect — individual brands vary significantly. Cogoi et al. (2012) found a 2.3x difference between the lowest and highest caffeine Argentine brands. But it's far more accurate than "30-180mg per cup."
What Surprised Me
Mate has MORE caffeine than most people think. A full gourd session (300-400mg) exceeds two espressos. The "mate is lighter than coffee" myth persists because people compare one refill to one cup of coffee — but nobody stops at one refill.
Temperature matters more than steep time. Cold tereré extracts ~35% less caffeine than hot mate with the same yerba and water volume. If you want less caffeine, go cold.
The "second mate" problem. Many South Americans share mate in a round (ronda). The first person to drink gets the most caffeine — by the 4th or 5th person in the round, each refill has less than a tea bag.
Theobromine is overrated. Many articles claim mate's "smooth energy" comes from theobromine. The actual theobromine content is 0.1-0.4% — about 10x less than caffeine. The smooth energy is from slow caffeine delivery, not theobromine.
Try It
Calculator: botanicaandina.com/herramientas/mate-calculator/
If you drink mate regularly and can report your experience with the estimates (accurate? too high? too low?), I'd love the feedback. The model improves with real-world validation.
Part of Botánica Andina — building open tools for evidence-based herbal medicine. Also check out our herb-drug interaction checker (250 plants, 401 interactions, all cited).
Top comments (0)