What is the right temperature for espresso? We tested it.

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

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

Even today, the rules of the World Barista Championship 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, p. 12

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

Anyone who can even determine the brewing temperature themselves on their espresso machine at home using PID control is more precise. Because we know: different brewing temperatures lead to different flavor notes in the cup.

In our Coffee Academy, we have calibrated all machines to 93° – always have. We like the coffees best this way, whether light or medium-dark – that means tastefully balanced and pleasant in texture. We also test all our coffee roasts at 93° in quality control. We can say that we have become accustomed to the 93° extraction temperature.

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

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

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

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

• Before each extraction, we purged the brew group for 5 seconds. On one hand to flush away the powder adhering to the shower screen, on the other hand to stabilize the temperature for sure. Then we inserted the portafilter directly 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 show a different side of the coffee.
• We made nine extractions each and removed the outliers at the top and bottom (learn more about espresso preparation)

Espresso extraction at 93°

Sensory evaluation

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

Espresso extraction at 96°

Sensory evaluation

• "Headache coffee" – the acidity was no longer well integrated, the bitterness was in the high range for 5 of 7 extractions
• the texture decreased noticeably for all coffees – although the TDS, that is the number of dissolved solids, was high, the coffee felt watery
• no coffee was really pleasant to drink

Espresso extraction at 88°

Sensory evaluation

• the coffee was dominantly sour, showing an unpleasant acidity that was not supported by sweetness
• the aftertaste was harsh and astringent
• no coffee could convince us this way

Findings

We tried to pull the extractions as identically as possible. The data set is limited, but gives an impression and initial trend. To substantiate all of this scientifically would of course require a larger test apparatus, more sensory evaluators, and various coffees.

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

Sensory

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

Extraction

• at 88°, channeling occurred multiple times – we had to repeat the extraction. We're still discussing what exactly the cause was
• the TDS variation was higher at 93° than at the other measured temperatures

TDS and extraction rate

• at 96° extraction temperature, more particles were extracted 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 tasty
• very light 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 became apparent 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. There we're experimenting with temperatures that are significantly higher than 93°, but also with different time ratios (extractions up to 60 seconds).

When it comes to taste, we could only really enjoy the 93° extractions.

Darker coffees tend to taste better at lower temperatures, as this particularly reduces the number of particles extracted from the coffee. The lower temperature also makes the coffee appear slightly fresher because it tilts slightly toward sourness – and that in turn gives the coffee better balance.

Darker coffees are already more soluble anyway and would have even more of a burnt taste and creamy texture at high brewing temperatures. For this reason, and of course there are always exceptions, we recommend for darker coffees a range of 91°-92° extraction temperature, for medium-light coffees 93°-94° and for light roasted coffees 94°-95°.

Our recommendations for the best espresso extractions

As so often, coffee is also a matter of taste here. Try it, compare and venture into new coffees – this way you'll learn quickly and find your personal standard for how you want to extract coffee.

We captured exactly how the coffees tasted in this video.

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