Coffee acidity can be significantly decreased through roasting, particularly for dark-roasted varieties. However, the exact level of acidity depends on its type and variety of coffee.

This study examined chromatographic detection thresholds and recognition for organic acids present in five lighter specialty roasting degrees of coffee from five sample origins, along with chlorogenic, malic, citric, acetic, quinic, and glycolic acids.

Acidity is a chemical property of a substance.

Acidity is a chemical property of substances which determines their ability to interact with certain metals and bases, measured on a pH scale from 0-7. Substances are classified as acidic when their hydrogen ions (H+) exceed the amount of hydroxide ions (OH-) present, but acidity can also refer to physical characteristics like hardness and viscosity of compounds.

13 coffee experts (mean age 29, 46% women) participated in a tasting experiment involving samples spiked with various concentrations of five organic acids. Assessors were trained to detect and recognize these acids both in water and coffee samples, receiving immediate feedback on correct responses; in addition, a 30-minute intensive training session in memorizing and identifying these acids was completed by each assessor.

Coffees used in this experiment came from various regions and cultivars, while their chromatographic data allowed for accurate quantification of acid concentration in each sample. Results demonstrated that concentration of phosphoric, malic, chlorogenic citric and lactic acids varied depending on roasting level; while formic acid concentration remained consistent.

After reviewing their findings, researchers came to the conclusion that focusing on individual acids found in coffee may be misleading and unlikely to contribute to taste differentiation between coffee varieties. Their sensory assessments consistently identified citric acid at concentration levels higher than average measured concentration in brewed coffee brews.

At the Coffee Quality Institute (CQI) and Specialty Coffee Association (SCA), it’s vital that coffee professionals be able to recognize various acids when comparing similar coffees. Both organizations dedicate significant portions of their training and examination material on acid recognition; such as citric, malic, lactic and tartaric acids are frequently included as examples; the latter also covers acetic and quinic acids acetic and quinic acids are included by SCA training and certification material as well. Litmus paper can help detect these acids when touched by acid; red litmus paper indicates acidity while blue litmus paper indicates basic substances.

It is a function of pH.

This study evaluated acid concentration in coffee samples from three roast levels – lighter, medium, and dark – using chromatographic separation technology. Results demonstrated that darker-roasted coffee had significantly less acid concentration compared with lighter roasted samples; nine to twelve individual peaks for acid were identified through this chromatographic separation; these included phosphoric, citric, malic, quinic glycolic formic and lactic acids but unfortunately there were no acetic or tartaric peaks identifiable.

As is widely acknowledged, coffee’s acid concentration varies with each method of brewing. Brewing temperature, grind size, and brew time all play an impactful role on its acid concentration (Khammitova et al., 2020). Furthermore, aroma profiles such as those commonly found in Kenyan coffee might impact perceived acidity as well; fruity notes could give an impression of higher acidity than would be predicted from its chemical makeup alone.

Sensory evaluation was carried out using the Identification of Tastes Test (ICT). Coffee experts were provided samples of water and coffee containing each of five organic acids and asked to identify which acid they had tasted from among a list. Data generated through ICT allowed researchers to determine threshold values for these acids; their analysis indicates that threshold values for acetic and citric acids are much higher than for the other acidic compounds.

ICT data further demonstrate that perceived acidity of coffee correlates strongly with its acid concentration. This finding is in line with chromatographic acid concentration measurements taken of samples, suggesting that acidity does not depend solely on individual acid concentration levels but on how these combine overall. Interestingly, Brazilian and Kenyan coffees differed considerably with respect to acid concentration; perhaps due to cross-modal aroma-taste interactions or synergistic effects between their main flavors of taste.

It is a function of temperature.

Acidity is an integral component of coffee’s overall perceived flavor. Acid is also essential for various physiological functions such as digestion and metabolism; however, too much acid can cause discomfort for those with sensitive stomachs. To avoid overdose on acids – something which could have serious health repercussions if done incorrectly – drink coffee that meets the appropriate body type requirements so as not to overdosing on acids that could have serious health implications; acids can be found in many fruits and vegetables which boast bitter or tart tastes, helping break down fats and proteins into biochemical pathways while helping you absorb vitamins and minerals from other food sources – therefore eating more fruits and vegetables will ensure adequate acid levels in your diet for maximum benefit!

Coffee has a pH value of approximately 4.5 and contains various organic acids such as citric, malic, and acetic acids in various concentrations, depending on its roasting process and origin.

Recent research investigated the acid composition of brewed coffee as it related to roast degree and sample origin, with results showing that individual acid concentrations varied systematically with roast level; chlorogenic acid decreased with increasing roast degree while citric and malic acids increased. Lactic and acetic acid concentrations varied significantly among sample origins.

This study also provided sensory detection threshold values and identification tests for citric, malic, acetic and phosphoric acids. For all three lighter specialty roasts tested in this study, detection threshold values ranged between 0.5-0.8mM; within this range most individuals would be able to distinguish spiked samples from unspiked controls.

Although it can be challenging to accurately predict the acid composition of coffee from its origin, this study concluded that its acid composition did not vary much across geographic origin, with chlorogenic and citric acids having more of an influence due to postharvest processing than cultivation or altitude.

It is a function of time.

A cup of coffee’s acidity depends on a number of factors, including water temperature, bean type and roasting method. Many individuals are sensitive to its acidic taste, leading to heartburn or stomach upset; this discomfort isn’t caused by acid itself but instead by chemical compounds known as carboxylic acid-5-hydroxytryptamide which acts like xenoestrogens that interfere with hormone balance in both men and women. If you want to minimize acidity then opt for low acid organic blends – however complete removal would change its flavor profile so it is best to find that balance between acidity and flavor for best results.

At this study, we evaluated the concentrations of five organic acids present in coffee. We measured concentrations of CGA, chlorogenic acid, citric acid, acetic acid and formic acid in French-press specialty coffee samples using French-press brewing technology. Next we conducted the 2-AFC test to assess sensory detection thresholds; using this method we found that average detection thresholds for these organic acids were significantly higher than in unspiked control coffees.

We discovered that as roast levels increased, chlorogenic and citric acids began to decline as thermal degradation of these compounds occurred during roasting. Furthermore, we observed that acetic and formic acids were more stable in roasted samples compared with unroasted controls.

Our results indicate a correlation between perceived acidity of coffee and its concentration of specific organic acids and its perceived acidity, but also other factors like masking or synergistic effects among taste chemicals.

Coffee producers must carefully select their green beans in order to craft premium, low-acid coffee. Furthermore, they must blend roasted coffees to produce an ideal blend – similar to creating a wine cuvee which involves selecting varieties to craft something unique with distinct style and taste.