Why is Coffee Bitter in the First place?

One of the things that would characterize the flavor of coffee would be the presence of a slight bitterness to its taste. People generally enjoy a slight hint of strong flavor in their coffee, after all it is what makes the beverage unique and a delight among the millions of people who enjoy it daily. Yet the thought of drinking overly bitter coffee is somewhat undesirable for most coffee enthusiasts. Utterly bitter coffee can mean many things, it may attribute to an over-roast or poorly blended coffee, overused beans that have been used more than they should or simply the loom of low grade coffee on your favorite coffee cup. Either way coffee bitterness is generally perceived as an undesirable yet permanent aspect of coffee in general.

Mild bitterness actually helps blend the acid taste which is also a flavor component in coffee and creates a delectable texture to the beverage, somewhat completing the coffee flavor. A coffee which is overpowering and extremely bitter on the other hand can create an imbalance in the flavoring aspect of the coffee and produce an undesirable taste, especially for consumers who like their coffee blended smoothly.

Scientific study into the bitterness of coffee has shown that the bitter taste from coffee is a result of chemical reactions between elements in the coffee and compounds found in the back of our tongue, particularly the circumvallate papillae. The taste of bitterness is often confused by many with coffee's astringency which is an entirely different characteristic altogether. Upon studying the chemical composition of coffee in general it has been found that the compound chlorogenic acid lactone is responsible for creating the bitter taste in coffee, lactones and phenylindanes in general are not bitter by nature but create the taste by undergoing a chemical reaction with compounds found in the papillae of the back portion of our tongue.

The production of the bitter compounds in the coffee we drink and the amount of it we ingest per sip will determine how bitter the coffee will taste like. In certain research it has been found that espresso for example has the probability of producing more of the bitter compounds and it's bitterness affected by the different temperatures, amount of beans and blend of coffee used to prepare the drink with it. Surprisingly, commercial grade coffee has been found to produce lesser of these bitter compounds compared to brewed coffee when they are prepared the same method as a high pressure brew because the bitter compounds found in them are destroyed in the process. Studies have shown that the same process that creates a higher bitterness in brewed coffee decreases the amount of bitterness in instant coffee by up to 40%.

Many scientists have backed up the findings regarding the influence of extraction with the amount of bitterness found in a coffee batch. The extent of extraction will always be relative to the roasting process and mineral levels of the water it is roasted in as well as the temperature, size of the grind and brewing system. This shows that the entire process of preparing the coffee affects the amount of bitter compounds present in it. Studies have shown that the use of distilled water during the brewing process greatly reduces the amount of bitter compounds in the coffee particles.

Scientists have also observed that the bitterness in a coffee preparation is directly related to the amount of solids dissolved once the coffee is prepared, which can also be influenced by the heightened armomatics produced when more coffee is disolved. Relatively this means that there is a perceived difference between the bitter taste of coffee as it is enjoyed hot versus prepared using a cold process. The use of hydrocolloids are also hypothesized to relieve the bitter taste of coffee. Compounds such as sucrose (C12H22O11), salt (NaCl) and citric acid (C6H8O7) are examples of such.

So How do you Make Coffee Less Bitter?

This has been a debatable question which many coffee enthusiasts have asked for a long time. Scientific inquiry into the bitterness of coffee however has provided important insight into different and proven methodologies of relieving the actual bitterness of coffee and the body's perceptive bitterness of it when we consume it.

  1. If you are looking for a mild and less bitter coffee, then make sure to use a medium roast when preparing the coffee solids. The solubility of coffee will greatly affect its amount of bitter compounds and medium roasted coffee contains lesser soluble compounds than high roasts. Using this type of coffee for your consumption will decrease the perceived bitterness dramatically.
  2. Studies have shown that the process of decaffeination also reduces the amount of bitter compounds in the coffee.
  3. The mineral influence of coffee before it is roasted can greatly affect its flavor and bitterness. Soaking fresh coffee beans in water a day before its roasting will affect the amount of bitter compounds and reduce the bitter taste of coffee once it is prepared.
  4. Using a coarse grinder will also decrease the bitterness by lowering the amount of soluble solids in the coffee preparation. The finer the coffee, the more soluble it becomes and more bitter compounds are added to the brew.