Introduction:Many people believe that hand grinders struggle to achieve the extremely fine grind required for espresso, but through practical testing, we found that with the right techniques, a conical burr hand grinder can also produce espresso with distinct flavors. In this session, we used a certain brand of hand grinder along with an Italian-style blend to walk through the entire process from adjusting the grind size to evaluating flavor performance, and we also shared the key differences between conical and flat burrs — providing a practical guide for those who want to challenge themselves by using a hand grinder for espresso.
It’s widely believed that hand grinders can’t produce the ultra-fine grounds needed for espresso, yet there are still some models on the market that claim to be up to the task. We specifically selected a certain brand of conical burr hand grinder, paired with a 3:7 Colombia and Brazil blend offered by a certain retailer. Using a professional-grade Yangjia 900N electric grinder as a benchmark, we systematically adjusted the grind size to closely observe how different levels of coarseness affected extraction flow rate, crema performance, and flavor profile.
For this test, we used a double basket filled with 20 grams of coffee, strictly controlling the standard parameters of a 1:2 coffee-to-water ratio and a 40-gram yield target. The ideal extraction time was locked in at the golden range of 25 to 30 seconds. For accurate comparison, we used the Yangjia 900N set to grind size 2 — known for its fine output — as a reference benchmark, and gradually adjusted the tightness of the hand grinder through multiple rounds of experimentation.
The actual test found that when the burr was adjusted back three notches from the initial zero mark, the resulting coffee grounds were finer than the reference standard, feeling as smooth as flour. When the grind size was further loosened to the fifth and ninth notches, although the feel was noticeably coarser, fine particles were still present. Notably, when attempting to make espresso with the ninth-notch grind size, we encountered a serious issue where liquid extraction was extremely slow, indicating the impact of uneven particle distribution.
After repeated testing, when the grind size was adjusted to the thirteenth notch, 20 grams of coffee only managed to produce 40 grams of liquid in 12 seconds. The resulting espresso had a light brown color with a thin crema layer. Upon tasting, it clearly exhibited excessive fruit acidity and a short-lived aftertaste, lacking the body that espresso should have — confirming that this grind size resulted in typical under-extraction. In contrast, the eleventh-notch grind produced a rich black liquid with a thick crema, but the 38-second extraction time led to noticeable burnt bitterness and smoky off-flavors.
The key breakthrough came at the twelfth notch: with an extraction time of 27 seconds — just right — the resulting espresso had a full-bodied golden crema. The flavor profile clearly showcased bright acidity notes of grapefruit, citrus, and berries, paired with a moderate level of bitterness and a sweet-and-sour balanced finish. This set of parameters successfully highlighted the unique nutty character of the blend, while avoiding interference from over-extracted impurities.
Looking deeper into the fundamental differences between conical and flat burrs, the conical burr mechanism primarily crushes coffee beans through a grinding action, producing particles that are less uniform and more prone to forming extra fine particles. In contrast, the flat burr design is based on a cutting principle, which results in more consistent particle distribution. During our tests, we found that even when adjusted to the ideal grind size, hand grinders inevitably produce a relatively high amount of fine particles, which can easily clog the filter and lead to uneven extraction.
For those wanting to try hand grinding espresso, it is recommended to start with a slightly coarser grind size and pay special attention to controlling the uniformity of the coffee particles. In practice, you can use a segmented grinding method — first pre-grinding a small amount to inspect the particle state, then fine-tuning parameters according to flow rate. In addition, regularly cleaning the burr grooves and keeping the bean hopper sealed are both important details for maintaining stable extraction. These practical tips can effectively reduce the occurrence of extra fine particles and increase the success rate of manual extraction.
The above content is compiled by CoffeeHunters, a coffee news website.
