What's the right temperature for espresso? We tested it.

The brewing temperature during espresso extraction is crucial for the taste. Light and dark roasts react differently to temperatures, but one thing they have in common is that too cold and too hot are not particularly delicious.

As recently as 2010, participants in the Swiss Barista Championships could specify how hot the machine should be set for the coffee they brought. Within a range of 90° - 94°, the technicians back then made it possible for baristas to set the machine according to the individual brewing temperatures for their respective espressos.

Even today, the rules and regulations for the World Barista Championships state that the machine should be set between 90.5° and 96°.

Espresso will be brewed on a machine with brewing temperature set to between 90.5-96degrees Celsius (195-205 degrees Fahrenheit)

Rules&Regulations, World Barista Championship, S. 12

This is somewhat surprising, as otherwise, every eventuality at the Barista Championships is defined more precisely. And the flavor range between 90.5 and 96 degrees is enormous.

All those who can even determine the brewing temperature themselves on their home espresso machine via PID control are more precise. Because we know: different brewing temperatures lead to different flavor notes in the cup.

In our coffee academy, we have always calibrated all machines to 93°. We found coffees, light or medium-dark, tasted best this way – meaning they were well-balanced in flavor and pleasant in texture. We also use 93° to test all our coffee roasts in quality control. We can say that we have grown accustomed to the 93° extraction temperature.

However, in forums, extraction recommendations from roasters, and other guides, we repeatedly find recommendations of 88° - 96° as the perfect brewing temperature. As mentioned, this is an enormous range and massively influences the taste.

We have described here how we measure the brewing temperature and how you can measure it at home.

Our test: the same coffee at 88°, 93°, and 96°

We wanted to know more precisely and set up an experimental apparatus. We tested a medium-light espresso roast at three different brewing temperatures.

• Before each extraction, we flushed the group head for 5 seconds. This was partly to rinse away any powder adhering to the shower screen and partly to stabilize the temperature. Then, we immediately inserted the portafilter and started the extraction.
• The blend of three coffees in equal parts helped us understand which facet of the coffee was emphasized. Alessandro is a fruity coffee, APAS is classically nutty-chocolatey, and Henrique has a bright acidity. We hoped that the respective extraction parameters would reveal a different side of the coffee.
• We performed nine extractions each time and removed the highest and lowest outliers (learn more about preparing espresso)

Espresso Extraction at 93°

Sensory evaluation

• as expected, the texture was medium-high and round
• the sweetness was clearly perceptible
• the acidity and bitterness were significantly higher in the 5th extraction than in the others (tbd)
• in 6 out of 7 extractions, the acidity was well integrated

Espresso Extraction at 96°

Sensory evaluation

• "Headache coffee" – the acidity was no longer well integrated; bitterness was high in 5 out of 7 extractions.
• the texture decreased significantly in all coffees – although the TDS, i.e., the amount of dissolved solids, was high, the coffee felt watery
• no coffee was truly pleasant to drink

Espresso Extraction at 88°

Sensory evaluation

• the coffee was dominantly sour, exhibiting an unpleasant acidity not supported by sweetness
• the aftertaste was tart and astringent
• no coffee was convincing

Findings

We tried to make the extractions as identical as possible. The data set is limited but provides an impression and an initial tendency. To scientifically substantiate all of this, a larger experimental setup, more sensory analysts, and various coffees would naturally be needed.

However, we were able to see and taste initial trends:

Sensory

• the medium-light roasted espresso tasted best at 93°
• a darker espresso we tested (but only with three extractions each) also tasted best at 93°
• the acidity of the 88° extraction temperature became unpleasantly sour
• at 96°, the coffee fell apart into its individual components and was no longer balanced

Extraction

• at 88°, channeling occurred several times – we had to repeat the extraction. We are still discussing what exactly caused this
• the TDS spread was higher at 93° than at the other measured temperatures

TDS and Extraction Rate

• at 96° extraction temperature, more particles were dissolved from the coffee, resulting in a higher TDS value
• the extraction rate was also higher, which is generally considered positive – but in this case, it simply wasn't delicious
• very lightly roasted espressos, however, perform significantly better at temperatures of 94° and higher
• a detailed test on this would be worth considering

Development of Extraction Rate and Taste

It became clear that higher temperatures result in a higher extraction rate. At the same time, it was shown that a higher extraction rate does not necessarily correlate with better taste – it really depends on the coffee. With the Decent Espresso Machine, we are currently testing brewing espresso with light filter roasts – and it tastes very good. We are using temperatures significantly higher than 93°, but also different time ratios (extractions up to 60 seconds).

Regarding taste, we could only truly enjoy the 93° extractions.

Darker coffees tend to taste better at lower temperatures because fewer particles are dissolved from the coffee. The low temperature also makes the coffee appear a bit fresher because it leans slightly acidic – which in turn gives the coffee better balance.

Darker coffees are already more soluble and would leave an even more burnt taste and chalky texture at high brewing temperatures. Therefore, and of course there are always exceptions, we recommend a range of 91°-92° extraction temperature for darker coffees, 93°-94° for medium-lighter coffees, and 94°-95° for lightly roasted coffees.

Our recommendations for the best espresso extractions

As is often the case, coffee is a matter of taste. Try it out, compare, and dare to try new coffees – this is how you will quickly learn and find your personal standard for how you want to extract coffee.

We have captured exactly how the coffees tasted in this video.

Want to learn more about preparing espresso? In addition to our articles, we recommend a visit to our barista courses. You can also participate digitally in our new online courses.