Despite no exact measure being defined for making the perfect espresso, there’s “a consensus” on maintaining certain criteria for preparing this ideal espresso. These are as follows:
- Coffee-water ratio: 1:2 – 1:2.5
- Type of grind: Relatively fine
- Brewing temperature: 92-96ºC (198-205°F)
- The coffee temperature in the cup: 71ºC (160ºF)
- Extraction pressure: Around 9 bars
- Preparation time: 5 seconds of pre-infusion and 20-25 seconds of infusion
If these values are altered too much, the resulting coffee will be far from a good espresso. This is why we must pay close attention to the temperature at which our Nespresso prepares the coffee and intervene if the temperature falls too low.
Thermoblock or thermostat failure
If the Nespresso machine detects a failure in the thermoblock or thermostat, the lights of the espresso and lungo buttons will begin to flash at a rate of 3 flashes every 2 seconds.
As explained in the article about the meaning of the lights on Nespresso coffee makers, the machine enters a failure mode and prevents the user from brewing any coffee. Therefore, if there is a failure in the thermostat or thermoblock, you will not notice any change in the coffee temperature, as you could not prepare it.
However, before one of these two components fails and is detected by the Nespresso, we might notice a lower temperature in our coffees. When we observe changes in the temperature of the drink obtained from our Nespresso, it is the ideal time to intervene and prevent bigger problems.
It is advisable to perform one or several descaling processes if the coffee temperature falls below 83ºC (181°F) during preparation, as limescale accumulation is the main cause of the low final coffee temperature.
How does the thermoblock and thermostat of a Nespresso work?
A standard thermoblock of a Nespresso machine can heat up to a maximum of 105 degrees Celsius, which is its maximum capacity by design. However, under normal conditions, it works at about 86 ºC (187ºF) since the thermostat connected in series opens and closes the circuit in a range of 83 to 89ºC (181-187ºF).
You should do a continuity test to check if a thermostat works with the coffee maker turned off (and disconnected from the network). If there is continuity, the thermostat works. However, on rare occasions, it could give continuity and work at an incorrect range of temperatures.
➡️ Related: Nespresso adapter for Dolce Gusto.
Tips to get hotter coffee from your Nespresso machine
These tips are easy to implement and can significantly improve the heat of your coffee, enhancing your brewing experience with your Nespresso machine.
1. Preheat your cup
- What to do: Fill your cup with hot water for about a minute before brewing your coffee.
- Why it helps: This warms the cup, preventing heat loss when pouring the coffee.
2. Run a blank cycle
- What to do: Before inserting the coffee pod, run your Nespresso machine with just water.
- Why it helps: This preheats the machine’s internal components, resulting in a hotter brew.
3. Choose a smaller cup size
- What to do: Select a smaller cup size setting on your machine if possible.
- Why it helps: Less water means quicker brewing, which helps to keep the coffee hot.
4. Add warm water to the reservoir
- What to do: Fill the machine’s reservoir with warm water (not too hot).
- Why it helps: Starting with a warmer water temperature leads to hotter coffee, especially for larger drinks like Americanos.
5. Regular machine maintenance
- What to do: Regularly descale and maintain your Nespresso machine.
- Why it helps: This ensures the machine heats efficiently, as limescale buildup can hinder heating performance.
6. Use insulated cups
- What to do: Brew your coffee into an insulated cup or mug.
- Why it helps: Insulated containers keep your coffee hot for longer.
Any failure of the thermoblock or thermostat will be detected and warned by the coffee maker, making it impossible to prepare coffee. So, in almost all cases, a lack of temperature in coffee preparation will be due to a buildup of scale on the internal walls of the thermoblock.
If, after several descaling processes, the problem is not solved, it is advisable to replace the thermoblock and thermostat. The bad news is that acquiring a new thermoblock is expensive (it can cost up to 70 euros) and, in addition, it is not easy to find.
The idea is to get a second-hand coffee maker that is broken, which has the thermoblock in good condition. These can be obtained on eBay for about 10 euros.
Frequently Asked Questions
What temperature should my Nespresso coffee reach?
Ideally, the temperature of the coffee in the cup should be approximately 71 degrees Celsius (160 degrees Fahrenheit). Nespresso normally operates at a brewing temperature of 83-89 degrees Celsius (181-192 degrees Fahrenheit).
How can I tell if my Nespresso machine has a problem with the thermoblock or thermostat?
If your Nespresso coffee maker has a problem with the thermoblock or thermostat, the lights of the espresso and lungo buttons will begin to flash at a rate of three flashes every two seconds.
What should I do if the coffee temperature is lower than normal?
If you notice a drop in temperature, it is advisable to perform one or several descaling processes, as limescale accumulation is the most common cause of the reduction in coffee temperature.
How does the thermoblock in a Nespresso machine work?
The thermoblock of a Nespresso can reach a maximum of 105 degrees Celsius (221 degrees Fahrenheit) but normally works at about 86 degrees Celsius (187 degrees Fahrenheit), controlled by a thermostat that operates between 83 and 89 degrees Celsius (182 and 192 degrees Fahrenheit).
What do I do if the temperature problem persists after descaling?
If the problem continues after several descaling processes, replacing the thermoblock and thermostat may be necessary. Consider the possibility of buying a second-hand thermoblock as a more economical option.