The water temperature is one of the most important factors to consider when preparing coffee. The ideal temperature is between 195ºF and 205ºF, depending on the extraction method, the coffee bean you use, its grind, and the degree of roasting.
Although the temperature is very important during extraction, I consider it a controlling factor, not a variable. I can vary the grind, extraction time, or ratio but keep the water temperature constant throughout the process.
Is boiling water used to prepare coffee?
Water boils at around 212ºF, a much higher temperature than the 195-205ºF I told you about earlier. Therefore, the answer is no. However, there are exceptions, which I will now explain.
- Not long ago, I told you how Turkish coffee is prepared; in this type of coffee, the water needs to boil to serve it. Therefore, Turkish coffee is prepared with boiling water.
- On the other hand, the well-known Moka pot requires the water to boil for it to pass (in the form of steam) from the lower chamber to the upper chamber.
- Finally, boiled coffee, which I also talked about in the blog some time ago, requires the water to boil to add the coffee just at that moment; therefore, boiling water is also used.
A coffee maker that uses a very high temperature is the electric drip coffee maker. The machine boils the water, evaporating it to condense and pass through the ground coffee. Therefore, it is water at a very high temperature without boiled water.
The importance of preheating your coffee maker before brewing coffee
It is very important to point out that with certain coffee makers, it is necessary to use hot water to preheat them. I am referring to all manual pour-over coffee makers, the French press, the Aeropress, and manual espresso machines.
The extraction methods that offer a more complex coffee profile are those where the user can better control the water temperature during pre-infusion. That is to say, manual pour-over and espresso.
It is possible to extract all the aromas, flavors, and notes from a well-pre-infused coffee. For this, it is important not only to control factors such as the amount of water used and the time but also the temperature of the water.
In a cold brewer, part of the temperature of the pre-infusion water will be transmitted to the cold material from which the brewer is made. This can lower the water temperature below 195ºF and affect the subsequent infusion process.
➡️ Use very hot water to increase the temperature of your coffee maker. This will subsequently favor a good extraction of the coffee.
What is the water temperature for manual pour-over coffee makers?
Manual pour-over coffee makers are of the Hario V60, Chemex, Kalita Wave, or Melitta type. It is essential to preheat the coffee maker well in all these coffee makers, as this will help prevent the water temperature from dropping too low during the pre-infusion.
All these coffee makers use paper filters where the coffee is placed, so the preheating not only serves to heat the walls of the coffee maker but also removes the paper flavor from the filter. Here you see a photo of the Kalita Wave, where I fold and place the filter and then preheat the coffee maker with boiling water:
The bean’s roast type influences the temperature of the water we are going to use, being able to lower the temperature a little if the roast is dark. However, using dark roasts with manual pour-over coffee makers does not make much sense, as it is always recommended to use medium/light roasts.
The ideal water temperature for manual pour-over brewers is 198ºF.
Generally, after preheating, I add the ground coffee and hot water at 198ºF for about 45 seconds. After this, I add the rest of the water at the same temperature.
What is the water temperature for the french press?
The French Press has no pre-infusion, so the problem of pre-heating can be avoided. Although this coffee maker can also be preheated, it will not significantly impact the resulting beverage.
With the French Press, we will have a wider range for temperature, with 195ºF for very dark roasts and water above 205ºF (almost boiling) for very light roasts.
Since I like medium/light roast coffees, I found the perfect water temperature is 203ºF.
Since the water will be in contact with the ground (coarse) coffee for 9 minutes, the water temperature will drop lower than in manual pour-over methods. This is one of the reasons why we want a slightly higher temperature.
➡️ Take a look at my recipe for preparing coffee with French Press.
What is the water temperature for the espresso machine?
The ideal water temperature for preparing espresso coffee, as in the previous cases, also depends on the type of roast.
For a medium roast with espresso machines, I recommend a water temperature of 198ºF.
Control of the water temperature in espresso coffee makers can be easier or more difficult, depending on the type of technology that each espresso coffee maker uses to regulate the temperature. We can find 3 types of technologies; thermostat, pressure switch, and PID.
Temperature control with thermostat
Domestic espresso coffee makers are usually equipped with thermostats. The thermostat is a very simple device consisting of metal plates that separate or join together depending on the temperature at which they are set. These plates are designed to separate when they reach 195ºF.
Note: If the ideal temperature is between 195ºF and 205ºF, why are they tared at 195ºF? This is because when they open the circuit, the boiler will heat a few degrees more, up to 198ºF or 200ºF.
- When we turn on the coffee maker, the thermostat is in its “closed” position and will allow the boiler to heat the water to 195ºF.
- When we start brewing coffee, the temperature drops below 195ºF, and the thermostat closes, allowing the water to heat up again.
- And so on until the coffee is finished brewing.
The problem with this temperature control system is that it rises above 195ºF when the thermostat opens the circuit and drops below 190ºF when it closes again. This produces a temperature variation during coffee extraction.
Temperature control with pressure switch
Most classic professional coffee machines use a pressure switch to control the boiler’s temperature. The pressure switch is based on the thermodynamic relationship between pressure and temperature to adjust the temperature according to the pressure.
These devices continuously monitor the pressure values of the boiler, so the temperature doesn’t need to drop too low to send the signal to heat the water again. The command is sent with minimal temperature variations according to the pressure drop.
Temperature control with PID
A PID is a temperature control system in coffee machines, where PID stands for Proportional, Integral, and Derivative. The PID connects to the boiler and controls its operation.
The PID adjusts the output of the system based on the ratio of the current temperature error, the cumulative integral of the error and the derivative of the error, with the objective of maintaining the water temperature in the boiler as close as possible to the desired temperature and avoiding abrupt changes.
Pablo Barrantes, Coffeemakerpedia.com
In the case of PID coffee makers, we are dealing with real computers that control the temperature of the water in the boiler. Thanks to this, the temperature variation of the water is minimal.
What happens if the water temperature is below 195ºF?
We have already mentioned that coffees with darker roasts need less temperature to extract their full potential. However, even these very roasted coffees need a minimum water temperature to deliver all the compounds and notes they retain in their interior.
Coffee prepared with water temperatures below 195ºF will be under-extracted. Normally it will be a more watery and less full-bodied coffee since not all the oils will have been extracted from the coffee.
What happens if the temperature is higher than 205ºF?
Earlier, I explained that the French Press, thanks to the thickness of the grind and the fact that the coffee is infused for almost 10 minutes, admits much hotter water, almost boiling. However, the rest of the extraction methods have a water temperature limit of 205ºF.
If you prepare a coffee with water at more than 203ºF, it is most likely that you will over-extract it (this is accentuated in darker roast coffees). The result is a bitter coffee with very harsh flavors, in addition to losing the more delicate notes, which are burned by the hot water.
Conclusion
Defining the right water temperature is crucial to preparing a perfect coffee cup. The ideal temperature is between 195°F and 205°F, but it can vary depending on the bean type, grinding grade, extraction method, and the degree of roasting.
Although the temperature is important, controlling other factors, such as grinding and extraction time, is also necessary. In addition, it is essential to preheat the brewer before preparing the coffee to avoid a significant drop in water temperature during pre-infusion.
- For manual pour-over brewers, such as Hario V60, Chemex, Kalita Wave, or Melitta, a water temperature of 198°F is recommended after preheating.
- There is no specific temperature in the French Press, but it is suggested to use hot water, not boiling, to prevent the coffee from burning.
In general, the water temperature is essential to achieve quality coffee, but it is also important to control other factors to obtain the best flavor and aroma.
