If you drink coffee, you have already tasted coffee acidity, even if you don’t know what it is. Coffee acidity is a primary taste associated with coffee.
There are several ways to test coffee acidity, including pH testing, extraction yields, titration, and cupping. We will discuss each one in detail.
Coffee acidity is the pleasing, jolting, sharp and tangy taste that you get on the tip of your tongue when you take a sip of coffee.
That distinct numbing sensation at the end of your tongue and the dryness on the sides and the back is caused by coffee acidity.
This acidity is a crucial aspect of the coffee drinking experience, which makes it a great indicator of the type and quality of coffee you are drinking.
Most avid drinkers can differentiate between high and low coffee acidity easily, just by taking a sip of their coffee.
However, it is beneficial to be able to properly test and measure coffee acidity, to determine the overall flavor profile and coffee quality.
Coffee Acidity Is Not the pH Level of Coffee
Most people confuse coffee acidity with the acidic pH level of coffee. The pH scale measures how acidic something is, which is why this confusion is completely understandable.
The pH scale values range between 0 (denoting the most acidic) to 14 (denoting the most alkaline or basic). Water is neutral, which is why it has a pH level of 7.
The pH level of coffee is slightly acidic, ranging anywhere from 4.5 to 6 on the pH scale, depending on the growing conditions and brewing method of the coffee beans.
Instead of the “pH level” of coffee, coffee acidity actually refers to the perceived taste of the coffee, which can be described as crisp, bright, sharp, and tangy.
In the world of coffee, acidity has more to do with taste, flavor, and coffee quality, than with the actual pH level of the coffee, despite the latter being an accurate measure of acidity.
What Exactly Is Coffee Acidity & Why Does It Matter?
Acidity is one of the most crucial components of coffee flavor, along with body, bitterness, and sweetness.
This makes it a key element in determining coffee flavor and quality, but not the only element.
Acidity in coffee comes from the presence of acids within the coffee beans.
Coffee beans contain several organic acids including citric, acetic, quinic, and malic acids in small amounts.
Various combinations of such organic acids contribute to the overall acidity and acidic profile (taste) of the coffee you drink.
The concentration of these acids in coffee beans can vary depending on a number of factors about the growing conditions of the coffee beans.
Factors like the climate, altitude, and the soil type in which the coffee plants grow can all impact the concentration of acids.
High-quality coffee beans usually have a higher acidity level than low-quality beans, mainly because acidity is a result of good growing conditions.
High-quality coffee beans are typically grown at high altitudes and in nutrient-rich soils with a favorable climate.
These conditions promote the production of organic acids in the coffee beans, resulting in a higher acidity level, and high-quality coffee beans.
For example, Arabica beans are known for their bright and fruity acidity, which is one of the factors that makes them higher quality coffee beans.
On the other hand, Robusta beans are low in acidity and high in bitterness. This off-balance makes lower quality coffee, and you’ll find Robusta beans being used in most instant coffees.
The roasting process of coffee and how the coffee is brewed can also have an impact on the acidity of the final product.
Darker roasts are roasted longer, which helps break down the organic acids, typically resulting in a lower acidity level.
Whereas lighter roasts preserve the natural acids, typically resulting in higher acidity.
However, it is important to note that roasting can also create new acids in the coffee, like chlorogenic acid, which can add a new dimension to the acidic profile of a coffee.
The brewing method also influences coffee acidity.
For instance, French press coffee tends to produce higher acidity than the same coffee brewed in a drip coffee maker.
This is because the French press allows for more contact between water and the coffee grounds, resulting in more extraction for a higher acidic level and more flavorful coffee.
Cold brew coffee, on the other hand, tends to yield lower acidity because of the slower brewing process that results in a lower concentration of acids extracted from the coffee.
A 24-hour cold brew coffee where you simply add coffee grounds to cold water, produces some of the lowest acidity, but makes for the silkiest, most velvety coffees you’ll ever have.
Ultimately, coffee acidity adds a refreshing element to coffee, making it more enjoyable to drink and providing that distinct tanginess of quality coffee.
Most importantly, however, coffee acidity is essential for balancing the overall flavor profile of coffee.
High-quality coffee is the most well-balanced coffee, and it should have the right amount of acidity, body, bitterness, and sweetness.
This overall acidic profile, with respect to other components like body and bitterness is what contributes to good taste and makes a high-quality coffee.
Acidity alone is not the only indicator of good or high-quality coffee, but it is an integral part.
Now that you have a good idea of what coffee acidity is and why it matters, let’s discuss how you can test coffee acidity.
How to Test Coffee Acidity
Testing coffee acidity is not an easy task and often requires a certain level of expertise.
Not to mention, some slightly complex and calibrated equipment is needed to measure the acidity level accurately.
Here are some of the main methods used to test coffee acidity:
Cupping is perhaps the simplest method to evaluate the quality and flavor profile of coffee, but it requires the most expertise.
Cupping involves brewing coffee in small cups and tasting it to determine its flavor and aroma. This professional practice is also done to test coffee acidity.
During cupping, expert tasters, professionally referred to as “Q Graders”, can evaluate the acidity of coffee by assessing the brightness, sharpness, and tanginess in its taste.
A coffee with higher acidity will have a brighter and more tangy taste, while a coffee with low acidity will have a duller and flatter taste.
Of course, the expert tasters also evaluate the color, aroma, body, bitterness, sweetness, and the balance of flavors in the coffee to test its overall flavor profile and quality.
However, coffee cupping is not just for professionals, and anyone can try it for practice or fun.
You can always gather some friends or coffee enthusiasts, brew some coffee in small cups, and start cupping together for fun.
Rate the coffee on color, aroma, acidity, body, bitterness, sweetness, and the balance of flavors, before comparing each other’s results.
As mentioned earlier, the pH level of coffee can tell you the acidity level of coffee on the pH scale.
pH testing is used to measure the acidic pH level of coffee, but not the acidic profile or “coffee acidity” in terms of taste and quality.
This is simply because it does not account for aroma, body, balance, etc.
Still, being higher on the pH scale indicates higher acidity, which can be one of several aspects of a high-quality coffee.
pH testing can be done using pH strips, but you can also use a more accurate pH meter.
To test the pH level of coffee, brew a small amount of coffee and let it cool down to room temperature. Then, insert the pH strip or meter into the coffee to measure its pH level.
The pH meter will likely give a digital reading on its screen, whereas you will have to pull out the pH strip and wait 15-20 seconds for the litmus paper on the strip to change color.
Compare the new color to the reference scale on the box of the pH strip to get an acidity reading.
Both results should range anywhere between 4.5 (high acidity) to 6 (low acidity), depending on the coffee beans and your brewing method.
Titratable acidity is another method to measure the concentration of acids in coffee. If you have ever practiced titration in your school’s chemistry lab, this is a similar process.
It involves adding a known and measured quantity of alkaline solution, such as sodium hydroxide (NaOH), to a coffee sample until the pH level reaches a certain level.
The amount of NaOH or alkaline solution required to reach this level is then used to calculate the titratable acidity of the coffee sample.
This is a slightly complex method of testing coffee acidity that requires some lab equipment, such as a burette and some volumetric glassware.
It also requires the knowledge to solve some basic chemical equations. However, it shouldn’t be too difficult if you still remember your high school chemistry lessons.
Another method to determine the acidity level of coffee is extraction yield. It involves measuring the percentage of coffee grounds or solids extracted during brewing.
A higher extraction yield typically means a higher acidity level, because more grounds have dissolved in the coffee.
This means there is a higher concentration of the original coffee beans inside the liquid coffee, which means more acids from the coffee bean are present.
The extraction yield can be measured using a refractometer, which measures the Total Dissolved Solids (TDS) or the concentration of dissolved solids in the coffee.
The higher the concentration of dissolved solids, the higher the extraction yield, and the higher the acidity level.
Once again, this is a measurement of the level or concentration of acidity alone, and not ‘coffee acidity’ in terms of the overall taste and quality of the coffee.
We hope you learned what coffee acidity is, and how it is not the pH level, but rather the perceived taste and acidic profile of the coffee—and how you can go about testing for acidity.
Coffee acidity is a crucial factor in determining the taste and quality of coffee, as it adds a crisp, refreshing, bright and tangy element to coffee, and balances the overall flavor profile.
While acidity levels can indicate greater coffee quality, other elements must also be accounted for to assess coffee quality.
Professional coffee cupping is perhaps the only method to roughly measure coffee acidity that also determines overall coffee quality.
Other methods like extraction yield and pH testing can help you determine the acidity levels of coffee more precisely, but not much else.
If you are a coffee grower, roaster, or even a coffee enthusiast, coffee acidity is essential for you to understand and measure, so you can evaluate the flavor profile and quality of coffee.
You should try out the mentioned methods, and test coffee acidity to learn more about all the types of coffee you drink or produce.
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