Have you ever suffered from acidity? If your answer is, "Yes", then tell me about your experience. What did you go through or feel because of it? Heartburn? If we relate the term 'acidity' to the food, then yes, there are some types of food which can cause heartburn because of their acidic nature. You should not go by this interpretation of the 'acidity', in the case of coffee as it is misleading. Because coffee's acidity, according to the experts, is a vivid taste experienced by the drinker as the chemicals in the coffee react with the taste buds of the tongue as well as in the throat. When it comes to suffering through the coffee cup, most commonly, the experience can be expressed as drinking overly sweet or bitter tasting coffee. It means that you have not yet found the coffee that is agreeable to your taste buds. Chemically speaking coffee acidity comes into play, when the acids presents in the brew donates protons to the receptors that are present on the taste buds. The acids present in coffee can be differentiated in three groups: alicyclic carboxylic and aliphatic, chlorogenic, and phenolic acids. The concentration of acids in the coffee brew depends on coffee roasting degree, type of roaster, and coffee brewing method. Factors Affecting Coffee The acidity caused by coffee depends on the type of coffee beans used, the soil and climate it was grown in, and the methods used to process the beans: wet process method or dry process method. Environment Coffee grown at high altitude and in volcanic soil that is rich in mineral is considered to be high in acidity. Coffee acidity levels in the Central American and East African coffee such as from Kenya and Ethiopia are high. While coffee grown in countries like Brazil and India are associated with low acidity levels. Processing Method Coffee beans that are processed with the wet processed method yields higher level of acidity than the once processed with dry processed method. How long you leave coffee powder in the boiling water or brew it, also has its say in how the coffee tastes. Brewing coffee for a long time, (more than 4 minutes) usually, imparts it a bitter taste which may again be due to excess coffee powder in your cup. Equating the bitter aftertaste after each sip of coffee to acidity is a wrong idea. Roasting Method Coffee's acidity also depends on how the beans are roasted. Too much depends on whether the beans receive the light roast or the dark roast. Both of these methods are used to dry out the beans by removing moisture from deep inside them. However, light roasted beans retain comparatively more moisture than the dark roasted ones. The amount of the moisture present in the coffee beans affect the acidity. The batch of the coffee beans prepared with light roasting will differ in acidity from the batch of the same type of beans that are prepared with dark roasting. This is so because the different degree of roasting process degrades different types of coffee acids to varying levels. Roasting degrades the chlorogenic acids mainly into quinic acid. A brew containing excessive quinic acid tastes sour. It happens when coffee beans are dark roasted or brew is heated for more time than it should be. Coffee prepared with the light roasted bean is sweet. The dark roasted beans lose out on sweetness, however, the coffee prepared with these beans is strong, crisp and plain. Some individuals have found that the coffee is not good for their stomach. In these individuals, the chemicals present in the brew i.e. acids that make the coffee acidic, upset the stomach. If coffee is consumed in excessive amounts, an individual may face a problem because of the caffeine in it. Caffeine changes the individual's body pH to acidic. There exists a relationship between acidity and the body's pH. It is essential for the human body to have a slightly alkaline pH for the healing process to continue. Researchers have conducted deep studies in the nature of coffee brew and have prepared the standard coffee acidity chart which can be referred to, before buying coffee for you. It must be noted that the coffee's pH is not linked to its flavor.