Can a conical burr hand grinder produce espresso coffee particles?

A conical burr hand grinder can handle espresso within limits. Testing the Timemore Chestnut G1S against a Yangjia 900N electric grinder, with Front Street's espresso blend of Colombia and Brazil at 3:7, a 20-gram dose, 1:2 ratio, 40-gram yield and 25 to 30 seconds, showed the hand grinder reaching espresso-fine settings and pulling workable shots after gradual adjustment.

Conical burrs produce blocky coffee particles, which lengthen the water path into each particle. Fewer solubles release early, so concentration does not spike quickly, and even with a longer extraction the woody material absorbs limited water, lowering the chance of off-flavors and astringency. Flat burrs behave differently, which shapes the practical advice for hand-grinder espresso.

Hand grinders are generally considered incapable of meeting the fine grind requirements of espresso, but there are indeed some manual grinders on the market that claim they can. In this article, we use the Timemore Chestnut G1S, a conical burr hand grinder, paired with Front Street Coffee's specialty espresso blend beans, and use the Yangjia 900N electric grinder as a reference. Through multiple extraction tests with gradual grind size adjustments, we observe the flow rate, crema, and flavor performance of espresso at different coarseness levels, analyze the differences between conical and flat burrs in grinding method, and finally provide practical advice for making espresso with a hand grinder.

I heard that some hand grinders are capable of producing extremely fine powder, enough to handle the grind requirements of espresso. Coincidentally, a colleague has a hand grinder that claims it can grind for espresso, so today we'll put it to the test and see what kind of espresso the coffee grounds from a hand grinder can produce.

Let's first get to know today's grinder — the Timemore Chestnut G1S.

This grinder is equipped with a conical burr set . The particles produced by conical burrs tend toward a blocky shape, which elongates the water absorption path of the coffee particles, requiring more time for water to penetrate the interior. As a result, conical burr particles release relatively fewer soluble substances in the early stage of extraction, and the concentration doesn't rise too high in a short time. At the same time, because the particles are blocky, even if the extraction time is prolonged, the woody part absorbs a limited amount of water, making the probability of off-flavors and astringency relatively low.

The beans chosen today are our Front Street Coffee specialty espresso blend beans ! Blended from Colombia and Brazil at a 3:7 ratio, this is an espresso blend that can meet the daily output needs of a café.

We're using a double-spout portafilter basket with a dose of 20 grams, a brew ratio of 1:2, a target extraction yield of 40 grams, and a desired extraction time of 25 to 30 seconds. The basic parameters are set; the most critical next step is finding the right grind size.

Since espresso-fine grounds can't be sifted through a sieve, we chose to use the Yangjia 900N espresso grinder as a reference, with the Yangjia 900N grind setting at 2.

Adjusting the Grind

First, tighten the grinder's burrs, using this position as the zero point, then back off one notch at a time. When backing off to 1 or 2 notches, the sound of burrs rubbing against each other could be heard, so we backed off directly to 3 notches and ground some beans. The result was even finer than the Yangjia 900N's grind, feeling like flour to the touch.

We coarsened the grind by two notches, backing off to 5, and although it felt slightly gritty, it was still very close to flour. We simply backed off all the way to 9, which felt somewhat close to the Yangjia 900N's coarseness, though it still felt like flour mixed with coarse particles. We tried grinding 20 grams of beans to make espresso and found that the coffee liquid struggled to drip out.

Backing off to 13, we made a shot of espresso at this grind setting, weighing 20 grams of grounds and extracting 40 grams of coffee liquid with an extraction time of 12 seconds. The espresso looked very pale in color, and the crema was thin. On the palate, the fruity acidity was prominent, the nutty flavor was weak, and the sweetness was short-lived. The extraction time was too short, indicating under-extraction, which meant the grind was too coarse.

This time we backed off to 11. Weighing 20 grams of grounds and extracting 40 grams of coffee liquid, the extraction time reached 38 seconds. The espresso looked dark in color with a thick crema. On the palate, it tasted burnt and bitter, over-extracted, with a slight smoky aroma, though the sweet finish was noticeable. This extraction time was too long, clearly over-extracted — the grind was too fine.

Setting 11 was too fine, and setting 13 was too coarse, so let's try setting 12! Weighing 20 grams and extracting 40 grams of coffee liquid, the extraction time was 27 seconds. The crema had a beautiful yellow color and looked quite full. On the palate, there was slight bitterness but lively acidity, with a sweet-and-sour finish, presenting grapefruit, citrus, and berry flavors — a very direct flavor expression.

Summary

Testing found that it is actually possible to make espresso with a hand grinder, only that it's quite labor-intensive . The flavor is relatively direct, with rich layers but not particularly well-defined — it feels like it goes straight from slight bitterness to acidity, then immediately to sweetness — and burnt bitter notes tend to appear easily.

We believe this is mainly because the Chestnut hand grinder uses conical burrs, while espresso grinders use flat burrs. Conical burrs primarily grind beans by crushing, whereas flat burrs primarily grind by cutting — which is also why grounds from conical burrs contain more ultra-fine particles. On top of that, a hand grinder isn't as consistent as an electric grinder, resulting in noticeable unevenness in particle size. So when using a hand grinder for espresso, it's advisable to grind slightly coarser to reduce the chance of excessive ultra-fine particles clogging the flow channels.

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