Can you boil coffee? (1 Negative Aspect)

In this brief guide, we will answer the question, Can you boil coffee? We will discuss some recipes and instances where you would consider boiling coffee. We will also instruct you on how to prepare coffee by the boiling method and some attributes that boiling coffee brings with it.

Can you boil coffee?

It has been estimated that 80–90% of adults are regular consumers of caffeine containing brews, such as tea, coffee, cocoa, cola, and energy drinks. A study on the caffeine intakes of the US population (considering a total of 37,602 consumers) showed that 85% of people consumed at least one caffeinated beverage per day (1).

Conventionally, you cannot boil coffee. Boiling coffee can deteriorate the taste of coffee. However, some coffee recipes require you to boil coffee, and some people enjoy the idea of drinking it.

People who do not have access to a coffeemaker sometimes resort to boiling their coffee. Turkish coffee and cowboy coffee are made by boiling the water. However, it should be only a few minutes when the coffee is exposed to boiling temperature, otherwise, it will turn bitter. 

Heat processing especially affects the flavor of the coffee. It was reported by studies that the decrease in the roasty odor after heating of the coffee drink was significantly caused by the decrease in the amount of three sulfur compounds (2-furfurylthiol, methional, and 3-mercapto-3-methylbutyl formate), and it was assumed that these odorants were changed by oxidation, thermal degradation, and/or hydrolysis (2).

What happens when you over boil coffee?

Considering the brew preparation at coffee shops, bars, or at home, several variables may modify the coffee quality in a cup. The type of contact between water and ground, the extraction time, the roasted-ground coffee/water mass ratio, the extract volume as well as water temperature, the vapor pressure in the case of Espresso coffee, filtration, and boiling process play important roles on the caffeine content of the beverage, as well as on functional and sensorial compounds (2).

When you make coffee, the ideal temperature lies between 202-206 F. If the temperature exceeds the 206 Fahrenheit mark, the coffee beans over-extract and taste burnt and bitter. The more you boil your coffee, the more bitter it tastes. Both caffeine and chlorogenic acid contributed to the bitterness, whereas the latter was also responsible for astringency (3). Studies showed that Turkish coffee, which is prepared by adding coffee powder into water and boiling for a few seconds, contains higher amounts of caffeine compared to other brewing methods (2).

 Over-boiled coffee tastes bitter because tannins leach out faster. The tannins are responsible for causing the bitter taste in coffee. Studies showed that some compounds, which give the roasty odor to coffee, are lost by heat treatment of brewed coffee. These odorants were changed by oxidation, thermal degradation, and/or hydrolysis during the heat processing. Furthermore, 2-furfuryl methyl disulfide and 4-hydroxy-2,5-dimethyl-3(2H)-furanone increased during the heat processing. These compounds were assumed to be responsible for the heavy (tallowy) and caramel-like odor (2).

For brewing add hot water, and make sure to take the coffee off of the heat. When you boil water, some advise that you cool it down for at least 30 seconds before you add it to the coffee to prevent freeze-dried ground beans from becoming over-steeped. However, others beg to differ and resort to boiling coffee.

Can you reduce coffee by boiling it?

If you end up with watered-down coffee, you may consider the idea of reducing it by boiling over a stovetop. However, some reasons point to why this may not be a good idea. 

Reducing coffee by boiling it can over-extract and sabotage the taste and flavor of the coffee. Boiling coffee for an undesirable length of time rips the aroma and compounds and makes the coffee bitter. 

Boiled coffee would be suited for people who do not mind an intense or bitter taste and flavor and are concerned by only the effect of the beverage.

Studies compared the aroma compounds of different brewed coffees prepared by different methods and showed that coffees which were heated after being brewed (ready to go coffee) generally had lower contents of most volatile compounds, indicating that the heat treatment significantly affected the aroma compounds that characterize the typical coffee aroma (3).

How to make coffee the old-fashioned way by boiling water?

To make cowboy coffee, you need to heat the water on an open fire or the stove and bring it to a boil. However, you need to monitor the temperature closely to prevent the coffee from getting over-boiled and turning too bitter.

 For Turkish coffee, however, the coffee is left on the heat for a few seconds.

Turkish coffee is slightly different from conventional coffee and has a distinctive taste that many may prefer but is too bitter for others.

Follow the recipe below to make Turkish Coffee;

In Turkey, Yemen, and Eastern Europe, a common practice for making coffee is by boiling it. To make coffee the Turkish style, you need finely ground coffee powder, a special coffee pot called a cezve, and no filter. The resulting beverage is coffee that is rich with a muddy texture.

  1. Grind your coffee beans to make them fine and fill up 5 ounces of cold water. Put the water on the stove on medium-low heat. 
  2. Add a teaspoon of coffee to your pot and do not stir.
  3. Add a tablespoon of sugar or according to your preference and let it dissolve on its own.
  4. When you observe that sugar has dissolved and the coffee has sunken to the bottom, you can stir the coffee pot and turn the heat down. You should turn the stove down at the last minute before it boils.
  5. As the coffee simmers, you will observe it foaming. Turn the stove off. Moreover, it will thicken and cool down.
  6. After you pour the coffee into your mug, give it a few minutes to settle down.

Follow the recipe below to make Cowboy Coffee;

Cowboy coffee makes for a terrific method to make coffee if you don’t have a coffee maker. You need to fill up some excess water to make up for the evaporation.

  1. Fill a pot with 13 ounces of water.
  2. Take a tablespoon of coffee grounds and pour it into the pot.
  3. Let the pot sit on medium heat until it boils. 
  4. Stir the coffee after 45 seconds of boiling.
  5. Put the coffee off of the heat after letting it boil further for no more than two minutes.
  6. After the coffee grounds settle at the bottom, brew for three more minutes.
  7. Get rid of the grounds by filtering or straining.

Other FAQs about Coffee that you may be interested in.

Why do people drink coffee?

Can you freeze brewed coffee?

Can you cold brew coffee in the fridge?

Conclusion

In this brief guide, we answered the question, Can you boil coffee? We discussed some recipes and instances where you would consider boiling coffee. We also instructed you on how to prepare coffee by the boiling method and some attributes that boiling coffee brings with it.

Citations

  1. Severini, Carla, et al. How much caffeine in coffee cup? Effects of processing operations, extraction methods and variables. The Question of Caffeine, 2017, 45-85.
  2. Kumazawa, Kenji, and Hideki Masuda. Investigation of the change in the flavor of a coffee drink during heat processing. J Agric Food Chem, 2003, 51, 2674-2678.
  3. Heo, JeongAe, et al. Analysis of caffeine, chlorogenic acid, trigonelline, and volatile compounds in cold brew coffee using high-performance liquid chromatography and solid-phase microextraction—gas chromatography-mass spectrometry. Foods, 2020, 9, 1746.