Is Salt Better Than Sugar in Coffee?! Science or Nonsense?

In the Greek film "A Touch of Spice," it was mentioned: Salt is the soul of the earth, life, and food. Because life needs food, and salt makes food more delicious～

Coffee is no exception.

Adding salt to coffee—does it sound strange? Compared to adding milk and sugar to coffee to adjust its bitterness or change the overall taste, the addition of salt not only reduces coffee's bitterness and balances the flavor but also enhances coffee's sweetness and can even bring out its aromas.

This practice is not unusual at all. Adding salt to coffee has been done for a long time. Traditionally, regions like northern Scandinavia, Turkey, Hungary, and even Siberia have all added small amounts of salt to their coffee. This "salty coffee tradition" is believed to have originated in European coastal areas.

Cultural Traditions of Salty Coffee

In Turkey, before marriage, the prospective groom and his family would visit the prospective bride's home. According to local tradition, the bride would prepare coffee for them and add a small pinch of salt to alleviate the bitterness that occurs when coffee is brewed at high temperatures～

If the future husband showed a satisfied expression while tasting the coffee, it was believed to indicate a good relationship ahead. In northern Scandinavia, consumers have been adding salt to brewed coffee for decades. In European coastal regions, brackish water with high salt content is often used to make coffee.

The Historical Origins of Salty Coffee

So why did the practice of adding salt to coffee emerge? After all, sugar could better mask the unpleasant flavors in coffee... However, before the mid-19th century in Europe, sucrose was considered a luxury that only the aristocracy could afford. Ordinary people wouldn't think of using sugar to season their food. When encountering food that didn't taste good, they would turn to seawater/salt for seasoning.

Additionally, the coffee beans shipped to Europe at that time were of very poor quality, and the brewing methods were simple and crude. Coffee beans were roasted until dark, then ground into fine powder, placed directly in a pot with water, boiled, and served. Bitterness became an inevitable taste in coffee.

But excessive bitterness was indeed hard to swallow, so people began experimenting with various seasonings to reduce coffee's bitterness. If they found something that tasted good, they would tell others: "Hey! Adding this makes it taste good!" Thus, salt became one of the ways people adjusted coffee's flavor. Because salt was the most easily available seasoning, only the practice of adding salt became widespread.

People at that time certainly didn't research why adding salt made coffee taste better—they simply passed on what tasted good. Even today, many people still add salt to their coffee, partly out of habit and tradition, and partly because they've discovered that adding salt to coffee not only reduces bitterness but also naturally brings out the coffee's sweetness while maintaining its pleasant aroma.

Scientific Validation

In 2009, food science expert Alton Brown suggested adding salt to coffee on his cooking show "Good Eats." He said that for every cup of water with two teaspoons of coffee grounds, half a teaspoon of salt should be added to neutralize coffee's bitterness. "Salt not only eliminates bitterness but also alleviates the 'stale' taste (off-flavors) in stored water." Later, scientific research was conducted on the relationship between salt and coffee bitterness, and studies proved that adding an appropriate amount of salt doesn't make coffee taste salty while being more effective than sugar at neutralizing bitterness.

Sources of Coffee Bitterness

Most of the bitterness in coffee is caused by two compounds: chlorogenic acid lactones and phenylindanes. Both compounds are produced during the roasting process as chlorogenic acids break down. Light to medium roasted coffee mainly tastes bitter because coffee beans contain more chlorogenic acid lactones. As roasting time extends and coffee beans are roasted darker, they contain more phenyl compounds. The more phenylindanes present, the sharper and more persistent the bitterness in coffee.

Additionally, coffee extraction also affects bitterness expression. Factors like brewing water temperature that's too high, grind size, too low coffee-to-water ratio, and extraction time that's too long can all increase coffee's bitterness.

Why Salt Reduces Bitterness

Unlike sweet, sour, salty, and umami tastes, the perception of bitterness is not a normal response on the tongue but rather taste buds releasing calcium ions, which then send "bitter" signals to the brain and activate bitterness receptors. The addition of salt (sodium ions) activates salt receptors on the taste buds. When sodium ions bind with salt receptors on the tongue, they can inhibit our perception of bitterness.

However, the addition of sodium ions doesn't "eliminate" calcium ions. Rather, the simultaneous presence of both creates a cross-sensory perception that not only inhibits bitterness but also enhances the taste buds' perception of other flavors, such as sweetness. This means that adding an appropriate amount of salt to coffee not only prevents salty and bitter tastes but also makes the sweetness in coffee more pronounced.

How to Add Salt to Coffee

Should salt be added to coffee grounds for extraction, or added after extraction? There's no exact scientific basis on how to add salt to coffee—just like when people first started adding salt, it was done according to preference. Since everyone's sensitivity to bitterness differs, it's recommended to add salt to brewed coffee. This way, you can determine the coffee's bitterness level and then add small amounts multiple times until reaching your preferred perfection.

Of course, when it's difficult to control, you can refer to the suggestion from coffee industry authority Scott Rao. He stated that whether for espresso or drip coffee, adding 0.15g of salt per 100g of brewed coffee yields the best taste.

When Not to Add Salt

Of course, not all coffee is suitable for adding salt. Adding salt can save a "failed" brew and reduce unpleasant flavors in coffee. However, if the coffee itself doesn't have unpleasant bitterness and has excellent flavor layers, adding salt will truly ruin it...

When good beans meet proper brewing, they exhibit appropriate bitterness. When the sweet, sour, and bitter aspects of coffee reach balance, the presence of bitterness is very pleasant.

Although adding salt to coffee still seems strange, curiosity always drives people to do "risky" things... I guess you're now heading to the kitchen to get salt, then intentionally or unintentionally ruining your coffee brew

Image source: Internet

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