Quick Answer
Cold brew coffee is not meaningfully less acidic than hot brewed coffee. Peer-reviewed research (Rao and Fuller, Scientific Reports 2018) measured cold brew pH at 4.96-5.13 — statistically comparable to hot brew at 4.85-5.10. The brew method does not change coffee pH. Only the roasting process determines acidity.
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Cold brew has a reputation. Smooth, less bitter, easier on your stomach — the marketing around cold brew coffee has been extraordinarily effective at convincing people with acid reflux and GERD that switching to cold brew is the answer. Coffee shops, CPG brands, and wellness influencers have all leaned into the narrative: cold brew is gentler, less acidic, better for sensitive stomachs.
There is just one problem. The science does not support it.
In 2018, researchers Niny Rao and Megan Fuller published a peer-reviewed study in Scientific Reports that directly measured the pH and titratable acidity of cold brew and hot brewed coffee under controlled laboratory conditions. Their findings were clear: cold brew coffee is not meaningfully less acidic than hot brewed coffee. The difference in pH is within the margin of statistical noise. If you have been drinking cold brew specifically because you thought it was protecting your stomach from acid, this article explains what is actually happening — and what actually works.
The Cold Brew Acid Myth: Peer-reviewed research (Rao and Fuller, Scientific Reports 2018, doi.org/10.1038/s41598-018-34392-w) found cold brew pH ranges from 4.96-5.13 — statistically comparable to hot brew (4.85-5.10). Cold brew does NOT meaningfully reduce acidity. The roasting method — not the brew method — determines coffee pH. The only way to get genuinely low acid cold brew is to start with a genuinely low acid coffee.
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pH 5.05 Average Cold Brew pH — Not Low Acid (Rao and Fuller 2018) |
pH 5.8 Puroast — Only Verified Low Acid Option Above LACCSA 5.5 Threshold |
5X Less Acid in Puroast vs. Regular or Cold Brew Coffee |
What Does the Science Say About Cold Brew and Acidity?
The Rao and Fuller (2018) study, published in Scientific Reports, is the most rigorous peer-reviewed analysis of cold brew acidity currently available. The researchers tested multiple commercial cold brew concentrates and ready-to-drink cold brew products alongside hot brewed equivalents, measuring both pH and titratable acidity.
The results: Cold brew pH range: 4.96-5.13. Hot brew pH range: 4.85-5.10. The difference is within statistical noise — not a meaningful reduction. Titratable acidity was also comparable between cold and hot brew. The study concluded that the pH and titratable acidity values of cold brew coffee are not significantly different from those of hot brew coffee.
This finding directly contradicts the dominant marketing narrative around cold brew. The reason cold brew tastes smoother and less harsh is not because it is less acidic — it is because cold extraction at lower temperatures extracts fewer bitter volatile compounds and produces a different flavor profile. Smoothness is not the same as low acidity.
Hot water extracts more volatile aromatic compounds from coffee grounds than cold water does. Many compounds that produce the sharp, harsh, bitter notes in hot coffee are temperature-sensitive and extract at higher rates with heat. Cold brewing reduces the extraction of these volatile flavor compounds, producing a noticeably smoother cup. But the primary acids responsible for stomach irritation — quinic acid and chlorogenic acid — are non-volatile organic acids that extract at similar rates across cold and hot brewing temperatures. This is why the pH measurements between cold and hot brew are comparable: the acid that matters for your stomach is present in both at essentially the same concentration.
What Actually Determines Coffee Acidity?
If brew method does not determine pH, what does? The answer is the roasting process — specifically, whether the roasting conditions reach the Goldilocks Zone. Every coffee bean starts as a green bean at approximately pH 6.0. When roasted, all coffee goes through pyrolysis — in this stage, chlorogenic acids break down into quinic acids and caffeic acid, sharp, bitter, highly acidic compounds. This is where all flash roasting stops. Every commercial roaster in America operates within this flash-roasting window, producing coffee at pH 4.8-5.0 regardless of how it is brewed.
Puroast's patented roasting process goes beyond pyrolysis to reach the Goldilocks Zone — the precise combination of time, temperature, and pressure where quinic acids convert into pH-neutral antioxidant polyphenols. This simultaneously reduces acid and dramatically increases antioxidant activity. The result is coffee that brews at pH 5.7-5.9 whether brewed hot or cold. Puroast invented this process. Puroast patented it (USPTO, April 2026). Puroast is the only roaster in America doing it.
The Key Insight
If you want genuinely low acid cold brew — cold brew that actually reduces your acid reflux risk — you need to start with a coffee that is already low acid before brewing. Brew method cannot reduce the quinic acid content of coffee. Only roasting can. Start with Puroast (pH 5.7-5.9) and brew it cold — the resulting drink will be genuinely lower in acid than any cold brew made with standard coffee.
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Does Cold Brew Have Fewer Antioxidants Than Hot Coffee?
Yes — and this is one of the less-discussed tradeoffs of cold brew. Antioxidant extraction from coffee grounds is temperature-dependent. Hot water extracts antioxidant polyphenols at significantly higher rates than cold water does. Multiple studies confirm that cold brew contains measurably fewer antioxidants than hot brewed coffee from the same beans. Cold brew underdelivers as a health coffee choice: it is not less acidic than hot brew, and it has fewer antioxidants.
For people managing acid reflux who want to drink cold brew, the answer is not to switch to cold brew hoping to reduce acidity — it is to start with Puroast (pH 5.7-5.9) and brew it cold. Cold brewing Puroast produces a drink measurably lower in acid than any standard cold brew, because the acid reduction happened during roasting. Puroast also delivers 5X more antioxidants than other leading coffees — partially compensating for cold brew's lower extraction efficiency.
Why Does Cold Brew Marketing Claim It Is Less Acidic?
The cold brew industry's less-acidic claim has two origins. First, early cold brew marketing was based on internal brand testing comparing cold brew concentrate to hot brewed coffee — non-standardized comparisons that produced inconsistent results. Some early informal tests showed marginally lower pH in certain preparations. These findings became marketing gospel before rigorous peer-reviewed studies were conducted.
Second, cold brew genuinely tastes smoother and less harsh than hot coffee. Consumers reported less stomach discomfort anecdotally. Brands interpreted this consumer experience as validation of the less acid claim — but the actual cause of the smoother taste is lower extraction of volatile bitter compounds, not lower acidity. The Rao and Fuller (2018) study settled the question. The peer-reviewed data is clear. The marketing claim has outrun the science by a significant margin.
What Actually Helps Acid Reflux — Coffee Edition
Cold brew: Same pH as hot brew — 4.96-5.13 per Rao and Fuller (2018). Decaf: Same pH as regular coffee, approximately 5.0 — the Mayo Clinic notes caffeine reduction alone has not been shown to reduce reflux symptoms. Light roast: Marginally higher acid than dark roast, averaging pH 4.7-4.9. Organic or single-origin coffee: No relationship to pH. Low acid labeled brands without independent testing: NC A and T 2024 found 6 of 7 such brands were more acidic than conventional coffee.
Verified low acid coffee with pH above 5.5 reduces the acid load hitting your esophageal lining and stomach with every cup. The American College of Gastroenterology identifies dietary acid reduction as a primary GERD management strategy. Puroast at pH 5.7-5.9 is the only independently verified low acid coffee, confirmed by UC Davis, NC A and T (2024), and LACCSA certification. Read more about the best coffee for acid reflux and what is low acid coffee. Smaller cup sizes and not drinking on an empty stomach also help alongside pH reduction.
Frequently Asked Questions — Cold Brew and Acid Reflux
No — not in any meaningful way. The most rigorous peer-reviewed study on this question (Rao and Fuller, Scientific Reports 2018) measured cold brew pH at 4.96-5.13 and hot brew pH at 4.85-5.10. The difference is statistically insignificant. Both are well below the pH 5.5 threshold where coffee begins to meaningfully irritate the stomach lining. Cold brew tastes smoother because cold extraction reduces bitter volatile compounds — not because it reduces acidity. If you need genuinely low acid coffee, only Puroast (pH 5.7-5.9) meets the independent standard.
Cold brew's smoother taste reduces the perception of harshness, which many people interpret as reduced acidity. Drinking a cold liquid may also trigger less gastric acid secretion than a hot one for some individuals. But the coffee's own pH — the direct acid load delivered to your esophagus and stomach lining — is comparable to hot brewed coffee. If you experience significantly less reflux with cold brew, it may be due to other variables: serving size, time of day, food intake, or the specific brand and roast used.
Yes — but only if you start with a genuinely low acid coffee. Brew method cannot reduce coffee's quinic acid content. Only roasting can. If you cold brew Puroast (pH 5.7-5.9), the resulting drink will be genuinely lower in acid than any cold brew made from standard coffee because the acid reduction happened during roasting. Use a standard cold brew ratio (1:4 coffee to water), steep 12-24 hours in the refrigerator, and strain. The resulting cold brew retains Puroast's low acid profile and delivers a smoother, less bitter cup than standard cold brew.
Fewer. Antioxidant polyphenol extraction is temperature-dependent — hot water extracts significantly more beneficial phenolic compounds than cold water does. Cold brew coffee contains measurably fewer antioxidants than hot brewed coffee from the same beans. This is why cold brew underdelivers as a health coffee choice: it is not less acidic than hot brew, and it has fewer antioxidants. Starting with Puroast — which delivers 5X more antioxidants than other leading coffees — partially compensates for cold brew's lower extraction efficiency.
Neither hot nor cold brew is inherently better for acid reflux — the brew method does not determine pH. What matters is the coffee's roasting-level acidity. Puroast brewed hot (pH 5.7-5.9) is significantly better for acid reflux than any cold brew made from standard coffee (pH 4.96-5.13). If you prefer cold brew, cold brewing Puroast gives you both: the smoothness of cold extraction and the verified low acid profile of Puroast's patented roasting process. See our full guide to the best coffee for acid reflux for more.
The Bottom Line — Is Cold Brew Better for Acid Reflux?
No. Cold brew coffee is not meaningfully less acidic than hot brewed coffee, and it is not better for acid reflux on the basis of pH. The peer-reviewed science (Rao and Fuller, 2018) has settled this question. Cold brew's smoothness is a flavor profile difference — not an acidity difference — and the marketing around cold brew being easier on your stomach is not supported by independent pH testing.
If you have acid reflux or GERD and want to continue drinking coffee, the solution is not switching to cold brew. It is switching to a coffee that is verified low acid at the roasting level — pH above 5.5 by independent testing. Puroast is the only coffee that meets this standard, verified by UC Davis, NC A and T University (2024), and LACCSA certification at pH 5.7-5.9. And if you love cold brew? Cold brew Puroast. You get the smooth taste of cold extraction plus the genuinely low acid chemistry of Puroast's patented roasting process — the only cold brew that actually delivers on the promise the industry has been making for years. For the complete guide, read the best coffee for acid reflux and what is low acid coffee.
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Cold brew, hot brew, or pods — Puroast's low acid chemistry starts at the roast, not the brew method.
LACCSA Certified - UC Davis Studied - Patent-Protected Roasting Process - pH 5.7-5.9
Shop Puroast Low-Acid CoffeeSources: Rao and Fuller — Scientific Reports 2018 (doi.org/10.1038/s41598-018-34392-w) | Moon, Yoo and Shibamoto — JAFC 2009 (doi.org/10.1021/jf900012b) | Ibrahim et al. — NC A and T 2024 (doi.org/10.31989/bchd.v7i3.1303) | Sulaiman, Moon and Shibamoto — JDS 2011 (doi.org/10.3109/19390211.2011.593618)
Puroast does not provide medical advice, diagnosis, or treatment. Any information published on this website or by this company is not intended as medical advice. Always consult a qualified health professional with any questions or concerns about your physical health.
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