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Low-Acid Options for Coffee Drinkers

The title alone of this article raises a sizable number of questions.

For example: What is acidity in coffee? The tart yet sweet sensation that animates the sensory character of the finest coffees and keeps them from falling into woody neutrality? An edgy sourness that messes up our tummies? Prime contributor to coffee’s newfound status as the leading contributor to cancer-fighting antioxidant activity in American diets?

All of the above, it seems. Including the last, perhaps unfamiliar definition. Because to further complicate the acidity issue, it turns out that organic acids in coffee, particularly those broadly described as chlorogenic acids, are major contributors to coffee’s antioxidant, cancer-fighting activity, which current research indicates considerably exceeds the antioxidant properties of beverages like green tea.

Goal: High Flavor, Low Acidity

So the question of the month: Are there coffees that can give us the flavor and the health benefits of a fragrant, lively cup while backgrounding the stuff that makes our stomachs sour?

And if so, where should an acid-sensitive yet flavor-sensitive coffee lover look for these garden-without-the-snake coffees miracles? In the form of naturally low-acid coffees? In other words, in the form of coffees that are naturally less acidy owing to tree variety and growing conditions? Or in the form of coffees that have been specially treated or roasted to reduce acidity?

We cupped twenty-five coffees for this month’s article, including a half dozen that were specially treated to reduce acidity and marketed as stomach friendly and/or low-acid, and about twenty that were not subjected to any special acid-lowering treatment, but came from origins – Brazil, Sumatra and India – whose coffees are relatively low-grown and generally associated with lower acidity. Let’s call this last group inherently low-acid coffees.

Flavor: Nature Trumps Treatment

By any sensory standards I know of, most of the inherently or naturally low-acid coffees we cupped were considerably more lively, complex and interesting than the coffees that were specially treated to reduce acidity. How much this difference has to do with keeping organic acids intact and how much with collateral damage to flavor caused by the effort to reduce organic acids is not clear.

Only the Tummy Knows

What about the heartburn and indigestion side of the question? Are any of these coffees definitely easier on the stomach than others?

Only the tummy knows. Two of the treated lines of coffee, Puroast and JJ Darboven’s Idee Coffee, cite academic studies to support their claims of lower acidity (Puroast) and less stomach irritation (JJ Darboven). These studies appear very limited, however, and when one factors in complicating variables, like how the coffee is brewed and whether it’s taken with milk and how fresh it was when studied (really fresh coffee is considerably different chemically from coffee ten days out of the roaster), these limited studies seem tentative at best in their application to the relationship of individual coffee drinker, individual stomach, and given cup of coffee.

Which doesn’t mean some of the coffees reviewed here, whether naturally low-acid or deliberately treated for low acidity, won’t be easier on the stomach than untreated, higher-grown and more acidy coffees. Most likely they will. But what this caveat does mean is that individual stomach owners may have to make up their own minds about the impact on digestion of some of these coffees by conducting private experiments; i.e. trying a couple and observing what happens afterward, from palate to tummy.

The Specially Treated Coffees

It appears that there are two fundamental approaches currently in play to reducing the tummy-suspect chlorogenic acids and their derivatives. The first is treating the green beans with steam to remove the waxy outer layer before drying and roasting them, the approach taken by the German company JJ Darboven for many years in its Idee Coffees, and also represented here by Hevla Coffees’ Low Acid Gourmet Coffee. The other way is by extending and slowing down the roast time, which measurably reduces chlorogenic acids and their derivatives. The Puroast line of coffees pursues this route: These coffees are roasted for a very, very long time – “Fifteen times longer” according to the packaging – in sealed drums. Folgers’ new brand of stomach-friendly coffee, “Smooth Roast,” does not divulge its stomach-irritant-reducing method except to suggest that it also is a roast-related process.

Despite the differences in approach to acid reduction, all of these coffees have one thing in common: their dominant flavor note is some variant of wood. This is not some snobby put-down, but a genuine sensory observation. The wood tones tend to differ from coffee to coffee, from rich wood (Darboven 85) to neutral wood (Hevla 83) to slightly charred wood (Puroast 84) to oddly salty wood (Folgers Simply Smooth 78). Not that wood is the only thing sensory thing going with these coffees, but it does form a common link and, in most cases, a dominant character. It is hard not to assume that these wood notes are what surface when you bake away aromatics, which is essentially what happens in extremely long, slow roasting, or steam off substances that contribute for flavor, which is what happens with the Darboven and Hevla coffees.

The JJ Darboven Idee Coffee (85), which reduces the chlorogenic acids before roasting and is relatively light-roasted, seems to preserve a bit more aromatic nuance than the other treated coffees.

Low Acid Coffees that Came that Way

Among the inherently lower-acid coffees we cupped this month, the Brazils, Sumatras and Indias, one stood out as a luminous sensory success: the Willoughby’s India Elkhill Estate (95). Freshly arrived as a green coffee in the United States, flawlessly processed and prepared, delicate and lyric, and perfectly if lightly roasted to foreground its natural sweetness and purity, this coffee was a revelation for me, similar to other Indias I have cupped over the years but a quietly complex apotheosis of their sweet, low-acid character.

How well the Elkhill Estate’s mild acidity and natural sweetness makes it a candidate for coffee drinkers with sensitive stomachs I really can’t say. But I suspect that brewed with a paper filter (rather than with a mesh filter or in a French press) it should be as “stomach friendly” as any of the other lighter roasted treated coffees, like the Idee or the Hevla.

This month’s focus on low acidity also attracted some other very fine inherently low-acid coffees, including the two Brazils (Barefoot Poco Fundo 90, Victrola Brazil Boa Sorte 88) and three Sumatras (Green Mountain Sumatra Reserve 90, Allegro Sumatra Blue Batak 90, Wood Fire Roasted Sumatra Mandheling 88). It may be that the Wood-Fire Roasted Sumatra (88), whose profile suggested it was very slow roasted, is as stomach-friendly as the considerably less flavorful Puroast dark-roasted blends.

Lower Acidity through Brewing and Buffering

Finally, a note about two other ways to reduce the potential of coffee to irritate the stomach: How you brew it and what you put into it before you drink it.

The cold-water brewing method, for example, extracts considerably less acid from the coffee than hot-water brewing methods. One of our sponsors, Toddy, sells an excellent little cold water brewing system ( Any of the 90-plus coffees reviewed here brewed in the Toddy system should produce a light-bodied, sweet, very low-acid, though perhaps aromatically simple black coffee that should be relatively easy on sensitive stomachs.

Or there is the espresso-and-milk option. Start with a mild espresso coffee composed of inherently low-acid coffees – over the years we have reviewed versions from Terroir Coffee, Paradise Roasters, Supreme Bean and others (if you don’t order by Internet try to find Illy Caffe at upscale grocers). Brew this coffee espresso-style in a short shot of an ounce or so and combine it with about three parts hot frothed milk for a beverage that still tastes like coffee but is quite easy on the digestive system (assuming the system’s owner is not lactose intolerant).

A Simple Test for Acidity: pH

Very general levels of acidity in brewed coffee in can be determined by a simple test of pH, or the relative acidity and alkalinity of a solution. Distilled water is neutral at 7. Numbers higher than 7 indicate solutions that are alkaline; numbers below 7 acid. Coffee generally is an acidy beverage, but a two-to three-point difference in pH is usually easily discernible on a sensory level by an experienced cupper, and may be significant in terms of impact on the digestive systems of acid-sensitive coffee drinkers.

The main lesson to be learned from this comparison is that darker roasted coffees are invariably less acidy than lighter roasted coffees, and degree of roast seems to make considerably more impact on acidity than does treating the green beans with steam. Both Hevla and JJ Darboven are steam-treated to remove acids, but the considerably darker roasted Hevla is measurably less acidy when measured by pH than the lighter roasted JJ Darboven. The Folgers Simply Smooth, which does not divulge its stomach-friendly strategies, is most acidy of all of the coffees we tested, again, probably because it is so light-roasted.

2007 The Coffee Review. All rights reserved.

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Posted in: Tasting Reports

About the Author:

Kenneth Davids is a coffee expert, author and co-founder of Coffee Review. He has been involved with coffee since the early 1970s and has published three books on coffee, including the influential Home Roasting: Romance and Revival, now in its second edition, and Coffee: A Guide to Buying, Brewing and Enjoying, which has sold nearly 250,000 copies over five editions. His workshops and seminars on coffee sourcing, evaluation and communication have been featured at professional coffee meetings on six continents.

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