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

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

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 the individual brewing temperatures for their respective espressos.

Today, the rulebook for the World Barista Championships still states 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 barista championships is defined more precisely. And the flavor range between 90.5 and 96 degrees is enormous.

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

We have calibrated all machines to 93° in our Coffee Academy — always have. We found that the coffees, light or medium-dark, tasted best that way — meaning well-balanced in flavor and pleasant in texture. We also test all our coffee roasts at 93° in quality control. We can say that we've gotten used to 93° extraction temperature.

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

We've 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 and set up a test apparatus. We tested a medium-light espresso roast at three different brewing temperatures.

• Before each extraction, we flushed the brewing group for 5 seconds. On the one hand, to flush away the powder sticking to the shower screen, and on the other, to ensure the temperature stabilized. We then clamped 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 highlight a different side of the coffee.
• We made nine extractions each and removed the outlier above and below (learn more about espresso preparation)

Espresso extraction at 93°

Sensory evaluation

• as expected, the texture was medium-high and round
• sweetness was clearly perceptible
• 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, bitterness was in the high range in 5 of 7 extractions
• the texture decreased significantly in all coffees – although the TDS, 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 predominantly sour, showing an unpleasant acidity that was not supported by sweetness
• the aftertaste was harsh and astringent
• no coffee could convince this way

Findings

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

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

Sensory

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

Extraction

• at 88° channeling occurred repeatedly – we had to repeat the extraction. We're still discussing what exactly caused it
• 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
• however, very light roasted espressos perform significantly better at temperatures of 94° and higher
• a more detailed test on this would be worth considering

Development of extraction rate and flavor

It became clear that higher temperatures result in a higher extraction rate. At the same time, it became apparent that a higher extraction rate doesn't necessarily correlate with better taste – it all depends on the coffee. With the Decent Espresso Machine, we're currently testing brewing espresso with light filter roasts – and it tastes very good. We're playing with temperatures significantly higher than 93°, but also with different time ratios (extractions up to 60sec).

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

Darker coffees tend to taste better at lower temperatures, as this primarily extracts fewer particles from the coffee. The lower temperature also makes the coffee appear slightly fresher, as it tips slightly toward sour – and that gives the coffee a better balance.

Darker coffees are already more soluble and would leave an even more burnt taste and creamy 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-light coffees, and 94°-95° for light roasted coffees.

Our recommendations for the best espresso extractions

As always, coffee is a matter of taste. Try it out, compare, and dare to try new coffees – this way you'll learn quickly and find your personal standard for how you want to extract your 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 visiting our barista courses. In our new online courses, you can also participate digitally.