Cold brew coffee has earned a reputation as a smoother, gentler alternative to hot drip coffee. Slow extraction at low temperatures does produce a less bitter, slightly less acidic cup. But gentle and genuinely low acid are not the same thing. For millions managing acid reflux, GERD, or gut sensitivity, that distinction is everything.
⚠️ The Science: Studies have NOT shown that reducing caffeine directly decreases acid reflux. Lower acid intake definitively helps. Cold brewing reduces acid marginally, but the roasting process locked in most of the acid before brewing begins. The only verified solution: Puroast traditional roasting at pH 5.82 — confirmed by NC A&T 2024.
The Only Verified Low-Acid Coffee
House Blend Ground or Whole Bean · 2.5lb Shop Now → |
Dark French Roast Ground or Whole Bean · 2.5lb Shop Now → |
Ugandan Single Origin Most Select Bean · 2.5lb Shop Now → |
| Coffee Type | Typical pH | Low Acid? |
|---|---|---|
| Standard hot brew | 4.8–5.1 | ❌ No |
| Standard cold brew | 5.0–5.4 | ❌ No |
| Most branded "low acid" coffees | 5.0–5.4 | ❌ No |
| Puroast hot brew | 5.82 | ✅ Yes — LACCSA |
| Puroast cold brew | 5.9+ | ✅ Yes |
The pH scale is logarithmic — which means a coffee at pH 5.0 is not slightly less acidic than pH 5.82, it is more than 6 times more acidic. This is why cold brew from standard beans — at pH 5.0 to 5.4 — still causes acid reflux symptoms in most sensitive individuals even though it "feels" smoother. The smoothness is real (cold extraction removes some bitter compounds) but the acid load remains high.
🌿 Key Insight: Cold brewing adds approximately 0.3–0.5 pH units compared to hot brew from the same beans. Since standard beans start at pH 4.7–5.0, their cold brew still only reaches pH 5.0–5.4 — well below the LACCSA verified threshold of pH 5.5. Only starting with Puroast beans at pH 5.82 produces cold brew that is genuinely, verifiably low acid.
Cold brewing reduces acid through two mechanisms: lower extraction temperature reduces the rate at which certain acids dissolve, and longer steep time does not significantly increase acid extraction the way it does for hot brew. The result is a coffee with approximately 67% of the acid of hot-brewed coffee from the same beans — a measurable reduction, but not a meaningful one when the starting point is pH 4.7.
Here is the chemistry: the primary acids in coffee — quinic acid, chlorogenic acid, and acetic acid — are formed during the roasting process, not during brewing. By the time beans hit the grinder, those acids are locked into the bean's chemical structure. Cold water extracts them less efficiently than hot water, but it still extracts them. The only way to reduce the acid before brewing is to change what happens during roasting. That is exactly what Puroast's patented slow-roasting process does — converting quinic acids into phenolic antioxidants before the bean is ever ground.
The process is simple — the key is starting with the right beans:
Step 1: Coarse grind Puroast beans (House Blend, Dark French Roast, or Ugandan Single Origin work best for cold brew).
Step 2: 1 cup grounds to 4 cups cold filtered water — this is the 1:4 ratio for concentrate.
Step 3: Combine, stir gently, cover and refrigerate 12–24 hours. Longer steeps (18–24 hours) produce richer, bolder concentrate.
Step 4: Strain through fine mesh lined with a coffee filter or paper towel. Press gently but don't squeeze — over-extraction increases bitterness.
Step 5: Dilute concentrate 1:1 with cold water for drinking. Serve over ice. Keep refrigerated up to 2 weeks.
The result: cold brew at approximately pH 5.9 — the smoothest, lowest-acid coffee cup format available. Compare that to Starbucks cold brew at approximately pH 5.0, and you understand why Puroast cold brew is in a fundamentally different category.
Best Puroast Varieties for Cold Brew
|
Dark French Roast Bold · Rich · Best for Cold Brew Shop Now → |
Mocha Java Chocolate Notes · Smooth Shop Now → |
Ugandan Single Origin Most Select Bean · Complex Shop Now → |
Cold brew is an excellent format for anyone with a sensitive stomach — but only when made with the right beans. Here's a complete guide for maximizing stomach comfort from cold brew:
Use whole beans and grind just before brewing. Pre-ground coffee oxidizes faster, producing more acidic off-notes. Grinding fresh right before the cold brew steep gives you the cleanest, lowest-acid result.
Filter twice. First through a fine mesh strainer, then again through a paper coffee filter. This removes the finest grounds and oils that can add bitterness and perceived acidity to the final cup.
Don't over-steep. 12–18 hours is optimal. Beyond 24 hours, even cold extraction starts pulling more bitter compounds that increase perceived harshness — though pH remains stable, the flavor becomes less pleasant.
Dilute to your preferred strength. Cold brew concentrate is typically 2X stronger than regular coffee. Always dilute 1:1 minimum. Many people with acid reflux do best at a 1:1.5 or 1:2 ratio (1 part concentrate, 2 parts water or milk alternative).
Try it with oat milk. Oat milk has a naturally high pH (6.5–7.0) and when combined with Puroast cold brew, further buffers the already low acid profile. The result is an exceptionally gentle, creamy cold brew latte that most acid reflux sufferers can tolerate easily.
Cold brew from standard commercial beans is lower in acid than hot brew from the same beans, but it is NOT genuinely low acid. Standard commercial cold brew typically measures pH 5.0 to 5.4, still below the LACCSA verified threshold of pH 5.5. Cold brew from Puroast beans — which start at pH 5.82 — reaches above pH 5.9, making it the only genuinely low acid cold brew available.
Most cold brew from standard commercial beans measures pH 5.0 to 5.4 — still classified as high acid by LACCSA. Cold brewed Puroast reaches above pH 5.9, producing the lowest acid cup available in any brewing format. Starbucks Cold Brew measures approximately pH 5.0. Puroast cold brew is nearly 10 times less acidic.
Cold brew from standard commercial beans may provide marginal improvement over hot brew but does not reach the pH threshold for clinically meaningful low acid classification. For genuine acid reflux relief, start with verified low acid beans — Puroast at pH 5.82 — and cold brew them for the most gentle result possible.
Puroast is the only cold brew base that gives you a genuinely low acid result. Any standard commercial coffee will still produce high acid cold brew because the bean chemistry starts at pH 4.8 to 5.1. Only Puroast's patented slow-roasting process converts quinic acids at the bean level before brewing begins. Dark French Roast and Mocha Java are the best Puroast varieties for cold brew.
No. Dark roasting produces only a 0.1 pH difference compared to medium roast. Dark roast cold brew is still high acid at pH 5.0 to 5.4 from standard commercial brands. The dark roast equals low acid myth does not apply to cold brew any more than it applies to hot brew.
12 to 18 hours in the refrigerator is optimal. Steeping longer than 24 hours does not significantly change the pH but can add bitter flavor compounds that decrease perceived quality. For the smoothest, most low-acid cold brew, 16 hours refrigerated is the sweet spot for most Puroast varieties.
Better Cold Brew Starts with Better Beans
The only cold brew base verified at pH 5.82 — 5X less acid than standard coffee. Cold brewed Puroast reaches pH 5.9+.
Shop Puroast Low-Acid Coffee →Sources: Moon, Yoo & Shibamoto — JAFC 2009 | Ibrahim et al. — NC A&T 2024 | Rao & Fuller — Scientific Reports 2020
Puroast does not provide medical advice, diagnosis, or treatment. Always consult a qualified health professional.
