Table of Contents
One of the most common questions is what is the right water temperature for espresso.
Ever wonder what makes the espresso a well-loved drink?
It is the bittersweet taste, the body, the aroma and its right amount of caffeine.
And the secret to getting all these from our favourite cup lies on nailing down the right water temperature.
The ideal water temperature to get an excellent espresso is 90.5 to 96 degrees Celsius (195 to 205 degrees Fahrenheit).
Moreover the water temperature has a direct impact on the other factors:
Let's get more into the details around the water temperature to extract a great espresso.
Brewing temperature is the temperature of water the moment it reaches the ground coffee.
The espresso temperature Celsius should be between 91 degrees to 96 degrees (195 to 205 degrees Fahrenheit).
Most people think that buying good quality coffee beans will instantly give them their perfect cup.
But in reality, getting the right coffee beans is just the beginning of the process.
After you purchase your coffee beans, you need to grind it.
There is also another set of standard for this.
Then, you must know the right dosage of ground coffee to achieve your perfect cup. And another set of standard in using an espresso machine.
But, all those things will be useless if you will use incorrect espresso brewing temperature Celsius during extraction.
If you will use a water less than 91 degrees Celsius (195 degrees Fahrenheit), this will not extract the ground coffee properly.
And if you will use a boiling water (100 degrees Celsius or 212 degrees Fahrenheit), this will just burn your coffee, and the result is undesirable.
However, if you will be using ground, frozen coffee beans, you should use 96 degrees Celsius (205 degrees Fahrenheit) as the moment the water reaches the ground coffee, temperature will drop upon contact.
Water temperature plays a significant role in determining the extraction yield and achieving a desired taste of the espresso.
Extraction happens when the water draws out the flavour from the coffee grounds.
Your favourite espresso shot is the result of this extraction. Sound easy, right?
In the study conducted by Andrew Easthope of Five Senses Coffee, he sampled forty (40) espresso shots (22 grams each).
Ten espresso shots were sampled for each temperature: 92, 94, 96, and 98 degrees Celsius.
His study used stockfleth distribution as the preparation method followed by single collapse on the bench and a very firm tamp.
He also used a single group-head and handle. Beverage weight and shot time were recorded for each extraction.
The study compared beverage, time, TDS (Total Dissolved Solid), and yield percentage for each temperature group.
Yield percentage is the total amount of extracted elements from the coffee.
The maximum yield percentage or the removable coffee mass is 28%, but we do not want to extract all the 28% because it will only make the coffee bitter.
The ideal yield percentage is between 18 - 22%.
The study showed a consistent upward trend on the yield percentage. Yield Percentage as follows:
However, on the TDS, the trend from 92 degrees Celsius to 96 degrees Celsius had an upward trend, but declined with 98 degrees Celsius.
TDS (Total Dissolved Solid) determines the strength of your coffee.
The ideal TDS ranges from 7.5 to 9.5%. Here's the TDS result:
The study shows that using different water temperature for espresso has a significant effect on the extraction.
Aside from the extraction, let's also see how it affects the taste of espresso shot.
The desirable taste of coffee might depend with the person tasting it.
Some like it sweet, some like it strong, and others like it bittersweet.
There are three (3) compounds we extract from coffee grounds that determines the taste of our beloved drink.
First is caffeine. Caffeine is a stimulant, and it is water-soluble.
This is the first compound that gets extracted from the coffee grounds.
Solubility means the ability of the compound to dissolve out of the grounds and into the water.
Next compound are the volatile oils. Volatile oils are responsible for the flavour and aroma, think about the smell of the freshly brewed coffee in the morning.
Volatility means the ability of the compound to evaporate into the air.
And the last compound are the organic acids. These organic acids are responsible for the bitter taste of coffee. They are the slowest to extract.
Based again on the research conducted by Easthart, the research I mentioned earlier, the products of his research on the effect of water temperature on extraction were also tasted.
All his samples were set aside for tasting.
He blind tested the cups to their staff, and here's the result:
Since it is already explained above how important the water temperature is, we should know about espresso machine temperature control.
This home machine can be controlled by calibrating the flush and steam switch with thermocouple thermometer.
This answers your question on how to measure espresso water temperature.
This most common machine can be controlled by the Barista by adjusting the pressure stat and flushing the group eight times, and see where the temperature stabilizes.
This one is much simpler than Heat Exchange.
It has efficient heating elements in the group that stops the groups from cooling down when the handle is not intact.
The water temperature has a huge impact on the overall taste of our coffee.
It is able to make or break the drink, despite having the highest quality coffee beans.
A study of 40 shots of espresso showed that having different water temperature during extraction shows significant difference on every shot.
The result of Yield percentage showed that the higher the temperature, the higher the Yield percentage is.
Although, the result can still be tested to more samples for a more accurate figure.
Aside from its effect on extraction, the temperature also has a significant impact on the taste.
Using low temperature (92 C) and high temperature (98 C) resulted to imbalance of compounds.
While using the middle temperatures (94 - 96 C) resulted in a good balance of compounds, thus producing the best tasting shot.
Given all the findings about the importance and effect of temperature, the barista must know how to control espresso machine water temperature.
And different machines require different techniques.
I hope you find this post helpful. Feel free to share your thoughts on the comments section below.