The Science Behind Yerba's pH
To understand yerba mate's acidity, it helps to review the pH scale. A pH of 7 is neutral (pure water), while anything below 7 is acidic and anything above 7 is alkaline. Most brewed yerba mate falls within the mildly acidic range, often between 5 and 6. However, some scientific studies have shown that specific preparations, like Brazilian chimarrão, can result in a pH closer to neutral (around 7.10), depending on the brewing conditions.
This discrepancy arises from several factors. The extraction of compounds during brewing, including caffeine and tannins, plays a major role. Tannins, in particular, are polyphenols that contribute to both bitterness and astringency, which can be mistakenly perceived as a strong acidic flavor. The concentration of these compounds is directly tied to the preparation method and product type.
Factors Influencing Yerba Mate's Acidity
The final pH and taste of your mate are not fixed. Several key variables influence its acidity:
- Brewing Temperature: Using water that is too hot (boiling) extracts more tannins and creates a more bitter, potentially more acidic brew. Conversely, using cooler water (around 160-175°F or 70-80°C) results in a smoother, less astringent, and less acidic-tasting drink. Cold brewing, known as tereré, produces a notably less acidic beverage.
- Water Quality: The pH of your source water can affect the final drink. Starting with filtered, pH-neutral water can help create a less acidic infusion. Some studies suggest using slightly alkaline water can further buffer acidity.
- Processing Method: The way yerba mate is processed significantly impacts its flavor and chemical profile. Smoked yerba mate (dried over wood smoke) can have a harsher, more robust flavor profile. Unsmoked, or air-dried, varieties tend to be lighter, cleaner, and perceived as less acidic. This is a major consideration for those with sensitive stomachs.
- Aging (Estacionamiento): Aged yerba mate undergoes a curing process that mellows its flavor and reduces bitterness over time. This process can break down some of the tannins, leading to a smoother, less astringent brew. Fresher, un-aged yerba can be more astringent.
- Milling Composition: Blends with more stems (palos) and less powder (polvo) contain fewer tannins and can produce a milder, less bitter infusion compared to those with a higher concentration of leaves and fine particles.
Yerba Mate and Digestive Health
While yerba mate is technically mildly acidic, many people find it much easier on the stomach than coffee. The primary compound causing stomach upset in coffee is often its high acidity combined with the rapid jolt of caffeine. Yerba mate provides a different experience for several reasons:
- Less Acidic Than Coffee: With a pH typically higher than coffee, yerba mate poses less of an initial acidic challenge to the stomach lining.
- Balanced Xanthine Content: Yerba mate contains a blend of xanthines, including caffeine, theobromine (also in chocolate), and theophylline. This combination provides a more balanced, sustained energy boost with less of the nervous, jittery side effects associated with coffee's caffeine.
- Saponins and Polyphenols: The saponins in yerba mate are believed to have anti-inflammatory effects, which can contribute to its gentler feel. The high antioxidant content also provides additional health benefits.
- Consumption with Food: For those prone to acid reflux or heartburn, consuming yerba mate on an empty stomach can still cause discomfort due to the caffeine content. Drinking it during or after a meal can help buffer this effect and reduce stomach irritation.
Comparison Table: Yerba Mate vs. Coffee
| Feature | Yerba Mate | Coffee |
|---|---|---|
| Typical pH | Mildly acidic (~5-6) | More acidic (~4.5-5) |
| Energy Boost | Smoother, more sustained, fewer jitters | Often leads to a rapid spike and potential crash |
| Digestive Impact | Generally gentler on the stomach, less likely to trigger acid reflux | Can exacerbate heartburn and acid reflux for sensitive individuals |
| Active Compounds | Contains caffeine, theobromine, theophylline, and saponins | Primarily caffeine, with higher concentrations |
| Antioxidants | Rich in polyphenols and high ORAC value | Rich in chlorogenic acids |
| Primary Flavor Component | Tannins and other botanicals | Roasted coffee bean compounds |
How to Make Yerba Mate Less Acidic
If you are sensitive to acidic foods and beverages, a few adjustments to your preparation can make yerba mate even gentler.
Use the Right Water Temperature
Avoid using boiling water, as it extracts more bitter tannins and can increase the perceived acidity. For traditional brewing, use water that is hot but not boiling, ideally between 160-175°F (70-80°C).
Try Cold Brewing (Tereré)
Making yerba mate with cold water reduces the extraction of bitter compounds and yields a lighter, less acidic-tasting drink. This is an excellent option for warmer weather and for those with sensitive digestive systems.
Choose Unsmoked Yerba Mate
For a smoother, cleaner finish, opt for air-dried or unsmoked varieties. The absence of smoke during the drying process often results in a milder flavor profile that is less astringent and gentler on the stomach.
Don't Oversteep
While yerba mate can be infused multiple times, shorter initial steep times can help control the extraction of compounds. Brewing for too long can draw out more tannins, increasing bitterness and perceived acidity.
Consider Water Quality
Start with filtered, neutral pH water. Some studies suggest a slightly alkaline water can reduce the frequency of quick washing in mate, implying a better pH balance.
Conclusion
In short, while yerba mate is technically mildly acidic, its pH is notably higher than that of coffee, making it a viable alternative for many with sensitive stomachs. The perception of acidity can be influenced by tannins, which contribute to astringency and bitterness rather than pure acid. By controlling key brewing variables like temperature, water quality, and preparation method, you can easily produce a smoother, less acidic-tasting cup. For those seeking a gentler, more sustained energy boost, yerba mate is a popular and effective choice over coffee, especially when enjoyed in moderation and with attention to your body's specific response.
Mayo Clinic - Yerba mate: Is it safe to drink?
