Acidity is a term frequently bandied about in coffee circles, but it's often misunderstood. Contrary to what many might assume, it doesn't refer to the pH level of your cup of joe. In the coffee world, acidity describes a bright, tangy, sparkly or crisp quality. A good acidity will make a coffee taste alive and is highly desirable in freshly roasted coffee.
The Science Behind Acidity
To understand coffee acidity in depth, it's essential to get a grasp on the science behind it. Acidity in coffee is predominantly the result of organic acids loaded in coffee beans. These acids form during the bean's growth phase and play a crucial role in the overall flavour profile of the coffee.
Acids like citric, malic, and tartaric might remind you of certain fruits when consumed. Citric acid, as the name suggests, is commonly found in citrus fruits. Thus, a coffee with high citric acid levels might have a hint of lemon or orange. Malic acid is found in apples, so coffees with high malic acid levels might possess apple-like acidity.
Factors Affecting Coffee Acidity
Altitude: Beans grown at high altitudes, where temperatures are cooler and beans grow slower, tend to have higher acidity. The prolonged growth period allows beans to develop a complex acid profile.
Processing Method: The way coffee beans are processed after harvest can also influence their acidity. Washed coffees, where the cherry is removed before drying, generally have a brighter and more pronounced acidity. In contrast, natural or dry-processed coffees, where the bean is dried inside the intact cherry, can have a more muted acidity.
Roast Level: The roasting process can either diminish or highlight acidity. Light roasts often retain most of the bean's inherent acidity. In contrast, dark roasts can reduce perceived acidity as the roasting process breaks down the acids in the coffee.
Acidity vs Sourness
It's essential to differentiate between acidity and sourness in coffee. While a bright acidity is often desired, sourness is not. Sourness can indicate under-extraction during the brewing process, meaning the water didn't pull out the pleasant tasting compounds in the coffee and left behind the less desirable ones.
The Balance in Acidity
Balance is vital in coffee. While acidity can add vivacity and life to a cup, it shouldn't overshadow other crucial components like sweetness, bitterness, and body. When brewed correctly, a coffee with balanced acidity will be vibrant yet harmonious, without any overpowering tartness.
How to Adjust Acidity in Your Brew
If you're keen to experiment with acidity in your brew at home or in your café, several variables can be adjusted. Grind size, water temperature, and brew time are key factors in the extraction process. Playing around with these can allow you to highlight or reduce the perceived acidity in your cup.
Grind Size: A finer grind can lead to over-extraction and a reduction in perceived acidity. In contrast, a coarser grind can lead to under-extraction, which might increase the sourness.
Water Temperature: Hotter water can extract acids from coffee more efficiently. If your brew tastes flat, consider increasing the water temperature slightly.
Brew Time: Extending the brew time can lead to more extraction and a reduction in acidity. If your coffee is too sour, try brewing it for a little longer.
Acidity in coffee is a complex and multifaceted subject. It plays a critical role in the overall flavour profile of a cup of coffee, contributing brightness, vivacity, and clarity to the taste. By understanding the science behind it and the factors that influence it, you can better appreciate the nuances in every cup and make adjustments to suit your palate.
Interested in bringing the best brews to your café? Moonshine Coffee is all about delivering top-quality beans with vibrant and balanced profiles. Partner with us, and let's elevate your coffee journey together.