Has it ever happened to you that you craved a specialty espresso, but after the first sip, you were surprised by an overly pronounced sourness? At Goriffee, we like to try new things, which is why we decided to test an old familiar trick whispered about in coffee circles: can a pinch of ordinary baking soda tame the wild acidity of coffee?
Our curiosity led us to a small blind test, the results of which surprised even experienced baristas.
The procedure was simple, but all the more interesting. We prepared two identical espressos. We secretly added a baking soda solution to one of them, while the other remained in its original, unaltered state.
We then served these samples to our "guinea pigs" – which included a champion barista and our colleague Peťo – and asked them for one thing: "Taste the coffee and focus on the acidity."
The tasting took place as a blind test, so no one knew which cup was "enhanced". The reactions were immediate.
When tasting the coffee with added soda, the tasters immediately noticed a difference. They concluded that "the first one was less acidic". Conversely, with the pure, unaltered espresso, it was noted that it had a more pronounced acidity, although it was still rated as pleasantly fruity.
The conclusion of our test at Goriffee is clear: Coffee professionals agreed that with just one teaspoon of baking soda solution, you can effectively reduce the acidity of espresso (or any other coffee with high sourness).
But what is most important for specialty coffee lovers – this intervention did not kill the coffee. Quite the opposite. Even after adding the soda, you could still taste its terroir and uniqueness, only the edges of the sharp sourness were pleasantly softened.
In our experiment, the tasters agreed on two key things: the coffee with soda was "less acidic", but at the same time, you could still taste its "terroir and uniqueness". Why didn't the soda kill the coffee's flavor completely, but only "smooth the edges"? Here is a deeper explanation:
Coffee is a naturally acidic solution with a pH usually between 4,5 and 5,0. This acidity comes from organic acids (chlorogenic, citric, malic) that give coffee its fruity character. Baking soda (NaHCO3) acts as a so-called buffer. When you add it to coffee, it dissociates and the bicarbonate ions react with the hydrogen ions (H+), which are responsible for the sour taste.
The reaction looks simply like this:
Acid (H+)+Soda (HCO3−)→Water (H2O)+Carbon dioxide(CO2)+Saltˇ
By removing the free H+ ions, you raise the pH towards the neutral number 7. This is exactly the moment when our barista noted in the video that the coffee is less sour.
This is the most interesting part. In the experiment, we heard that the coffee retained its "pleasant fruitiness" and character. Why didn't it turn into boring brown water?
During neutralization, a small amount of salt (sodium) is created as a byproduct. In food science, it is known that sodium ions have the ability to suppress bitterness and at the same time enhance the perception of sweetness. So the soda did two things at once:
1. Physically reduced the acid concentration (neutralization).
2. Sensorially "tricked" the tongue, to perceive the coffee as sweeter and smoother, allowing the terroir to stand out without a distracting "sharp" tail.
3. Selective effect
Dosage is important. As we saw in the video, just "one teaspoon of solution"was enough. If you poured soda directly into it, the reaction would be too violent and the coffee would taste soapy and flat. A small amount only softens the most aggressive acids (e.g. acetic), but leaves the complex aromatic compounds untouched.
Do you have coffee at home that is just too "wild" for you? Try our trick. Prepare a solution of water and soda and add it drop by drop to the coffee until you find your ideal balance.
As we say in the video: "Try it yourself and let me know in the comments how it turned out."
Analogy in conclusion: Imagine baking soda in coffee as an equalizer on a stereo. Coffee is a song you like, but the treble (acidity) is pulled up so explicitly that your ears hurt. By adding soda, you don't change the song or the singer (the terroir remains), you just pull those sharp highs down to a level that is pleasant and harmonious for your ears (and tongue).
