Introduction:Espresso is commonly made with medium-dark or dark roasted beans, but if you want to try light roasted beans with prominent fruity and floral notes—such as berries and cocoa flavors—you often encounter extraction issues that lead to overly sharp or dull-tasting shots. This article explains the five key parameters you must adjust when switching from dark to light roast: grind size, dose, extraction time, brew ratio, and milk proportion, helping you master the correct technique to pull a balanced and layered shot of espresso.

Espresso is generally brewed using medium-dark or dark roasted beans because their caramelized aromas harmonize better with milk, making them ideal for drinks like lattes or cappuccinos. However, drinking dark roast flavors exclusively can become monotonous over time, leading many coffee enthusiasts to experiment with light roasted beans that highlight fruity and floral notes—such as those with berry and cocoa aromas—in hopes of showcasing different layers and nuanced textures in their milk-based coffee.

But light roast and dark roast coffee beans differ significantly in density and brittleness. If you directly apply the extraction parameters used for dark roast, it often results in espresso that is overly sharp, with pronounced acidity, and an unbalanced mouthfeel once milk is added. Therefore, if you want to achieve satisfying espresso with light roast beans, you must adjust several key variables.

First and foremost, the most critical adjustment isgrind size. Compared to dark roast, light roast beans have higher density and lower brittleness, so under the same grind settings, the resulting coffee grounds will be coarser. This causes water to pass through the coffee puck too quickly, leading to insufficient extraction time, which affects flavor release and may even trigger channeling—where some areas are over-extracted while others are under-extracted.

To improve this, it is recommended toadjust the grind finer by 2 to 4 notches. The exact adjustment can be fine-tuned based on actual extraction results, with the goal of slowing down the water flow so that the coffee grounds are fully extracted, releasing the intended aroma and balanced acidity and sweetness.

Next is thedosesetting. Because light roast beans are denser, they weigh more for the same volume, so their stacking behavior in the portafilter basket differs from that of dark roast beans. To maintain an appropriate puck thickness and stability, it is recommended toincrease the dose by about 0.5 to 1 gram, reducing the gap between the puck and the shower screen to lower the chance of channeling and ensure a more uniform and stable extraction.

Additionally, fine-tuning the dose can also help regulate pressure performance, making the extraction process smoother and contributing to overall better extraction quality.

In terms ofextraction time, dark roast beans are typically extracted within 25 to 35 seconds, whereas light roast beans, due to slower release of flavor compounds, are recommended to be extracted for28 to 40 secondsor even slightly longer depending on the situation. Extending the extraction time ensures more flavor components are drawn out, especially those acids and sugars that take longer to dissolve, resulting in a smoother and more layered coffee taste.

Note that the time referred to here is the actual extraction time, excluding the pre-infusion phase.

Adjusting the brew ratio is equally crucial.Dark roast beans often use a 1:2 brew ratio, but because light roast beans have relatively pronounced acidity, it is suggested to widen the ratio to around1:2.5to increase the weight of the extracted coffee liquid. This improves the overall extraction yield, allowing more flavor compounds—especially bitter and sweet elements—to be released, helping to balance the sweetness of the milk and preventing the acidity from dominating.

Finally, if you’re using light roast espresso for milk-based drinks like lattes or flat whites, it’s advisable tomoderately reduce the amount of milk. Light roast beans usually have a fresher, more subdued flavor profile, and if the milk proportion is too high, the inherent coffee character can be easily masked, turning the final drink into “coffee-flavored milk” and losing the delicate fruit acidity and aroma that light roast beans aim to deliver.

When adjusting the milk ratio, you can experiment gradually based on personal taste to find the optimal balance between coffee and milk, allowing their flavors to complement rather than overshadow each other.

All the above adjustment suggestions are based on the premise that the coffee beans are fresh. Within 4 to 45 days after roasting, coffee beans contain moderate levels of carbon dioxide, which helps preserve aroma and flavor compounds. However, if stored for too long, the aroma will dissipate rapidly. Therefore, it is recommended to choose freshly roasted beans, ensuring they are still in their best flavor state upon arrival, to facilitate the extraction of the most ideal espresso.

The above content is compiled by CoffeeHunters, a coffee news website.