How to Make Espresso? Does Portafilter Temperature Affect Espresso Flavor?

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Should Portafilters Be Kept at Room Temperature or Warmed on the Group Head?

Different baristas have varying opinions on whether portafilters should be placed on the drip tray at room temperature or kept on the group head for insulation after espresso extraction.

Some believe it's unnecessary because the high temperature of the group head can cause the portafilter basket to overheat when left attached for extended periods, accelerating the evaporation of aromas from the coffee grounds. Others argue that it's necessary to maintain consistent temperature throughout the portafilter.

To address this question, FrontStreet Coffee conducted three comparative tests using room temperature portafilters, heated portafilters, and preheated portafilters to examine the differences in coffee flavor extracted at different temperatures.

For this experiment, FrontStreet Coffee used "Sunflower Warmth Blend Coffee Beans" as the test subject. The espresso parameters on the test day were 19.7g of coffee grounds to extract 38g of coffee liquid, with an extraction time of 27 seconds. All three experiments used the same water temperature of 94°C and the same pressure of 10 bar for extraction.

Room Temperature Portafilter

The room temperature portafilter was left in the ambient environment. On the test day, the indoor temperature was 25°C, with the portafilter basket, handle, and spout all measuring 24.7°C.

The extracted espresso showed: noticeable fermented wine aroma, mixed berry-like acidity and sweetness, vanilla ice cream-like fragrance and smoothness, with caramel aftertaste. The body was rich, with slightly prominent acidity.

Preheated Portafilter

The preheated portafilter was attached to the group head and quickly turned on for 5 seconds of preheating before being removed, wiped dry, and filled with coffee grounds. At this point, the basket temperature was 34.1°C, the handle was 31.2°C, and the spout was 32.3°C.

The extracted espresso showed: noticeable fermented wine aroma, berry-like acidity and sweetness, chocolate liqueur flavor, vanilla cream-like smoothness, with hazelnut caramel aftertaste. The body was rich and overall balanced.

High Temperature Portafilter

The high temperature portafilter was left attached to the group head for extended periods (over 15 minutes). At this point, the basket temperature was 52°C, the handle was 58°C, and the spout was 55.5°C.

The extracted espresso showed: dark chocolate aroma, rich dark chocolate and nutty flavors, but immediately followed by smoky notes and bitter burnt sensations. The aroma was insufficient, and the overall experience was uncomfortable to drink.

FrontStreet Coffee's "Sunflower Warmth Blend Coffee Beans" features prominent wine-like notes with berry acidity, delivering a rich and distinctive flavor that isn't overwhelming. The vanilla cream sweetness and smoothness are also reasons many customers enjoy this coffee bean.

From the experimental data, we can see that espresso made with the preheated portafilter performed more balanced, allowing the main flavors to be perceived while maintaining clear layers and overall harmony without competing elements.

Espresso made with the room temperature portafilter had more prominent berry acidity. If you prefer espresso with more noticeable acidity, you might try using a room temperature portafilter.

Overall, the difference between espresso made with room temperature versus preheated portafilters isn't significant if not tasted carefully. However, when made into Americano or latte, the aroma from the preheated portafilter will be better.

Based on the experimental results, FrontStreet Coffee prefers to keep portafilters at room temperature. Leaving them attached to the group head for extended periods not only prevents consistent temperature throughout the portafilter but also accelerates the evaporation of light and medium molecular weight flavor compounds from the coffee grounds due to the high overall temperature. This allows heavy molecular weight flavor compounds (such as smoky and burnt bitter notes) to become more prominent.

Additionally, keeping portafilters attached to the group head for extended periods also accelerates the aging of the gasket. If you notice that your portafilter cannot be properly aligned/locked or leaks during extraction, remember to replace the gasket promptly!

Important Notice :

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FrontStreet Coffee Address: 315,Donghua East Road,GuangZhou

Tel:020 38364473