@zellleonhart: Thank you for that.

OK, I think we've covered the [possible] slogan interpretations and it's time to move back on topic (i.e., along the lines of the site's slogan "your guide to exceptional espresso/coffee" ). Putting the thread on cooldown so this message is not overlooked. Thanks.

I had been looking to upgrade the Hario Slim grinder I keep at work paired with a Nanopresso. With cyber week sales, I picked up the Kingrinder K3 (recommended for espresso) for under $100. I really like it.

This was a big upgrade on various fronts. First, compared to the Hario, it has a good range for espresso. The 18-micron adjustments are significantly better and smaller than in the Hario. If I were using this exclusively on my home machine, the 18-micron steps would be a downgrade from my stepless Eureka mignon silenzio. Yet, though the burrs are not yet fully seasoned, I had no problem dialing in a single-origin medium roast coffee from a third-wave roaster on my Profitec 300. The shot was delicious and complex. I will continue experimenting to get a sense of what one-step translates in terms of shot time.

Second, grinding fine enough for espresso is significantly faster and less strenuous than on the Hario. I can grind through 18g of a medium-roast bean in about 55 seconds. For the Nanopresso, which has an 8gr basket, it's less than 25 secs. The larger bearing in the K3 also makes it smoother. In my opinion and my location, both produce about the same amount of static and minimal retention. I simply tap the K3 on a rubber pad before opening the dosing cup.

Thirdly, the cylinder for the K3 is smaller and very solid. Compared to the Hario's mostly plastic components, the aluminum body and the lever with its wooden knob looks, of course, much nicer. The rubber wrap around the body gives good grip. At the same time, the K3 is heavier, though I have not found it taxingly so.

I was tempted to pick up the K4 with the exterior adjustments and 16-micron steps but, given my needs, I was happy with the lower price of the K3. Maybe the 2-micron step difference would be much more worth it if this was my primary grinder. And, though I haven't tried a hand grinder with external adjustments and my only comparison is the Hario, I find the internal adjustments perfectly acceptable and not inconvenient.

I think this is still the honeymoon period with this grinder. I'm sure that the further away I get from the Hario experience and the more use I give this grinder, occasionally testing it with other brewers (aeropress, chemex, etc.) I'll run into its limitations. I'll try to share impressions as that happens.

I'm glad to say that I've now tried two Kingrinder models, and I think they're excellent. Fully delivering on what they promise and with value-for-money that's clearly ahead of 1Zpresso and other brands. I bought a Kingrinder K2 recently and also have access to a K4 (owned by a friend) and I made some comparison between these two and the other manual grinders that I own - 1Zpresso K-Plus and JX Pro, and an old Hario MSS-1B.

My conclusion is that the K2 has the best balance of the group when it comes to speed and ease of grinding. It can handle light roasts very well, while both the K4 and K-Plus required a lot of effort to grind such beans and had many stalls. The JX Pro also worked well, but is slower than the K2. Considering that the K2 can be had for 75 USD shipped (from aliexpress.com) I think it represents unbelievably good value.

Below are some of my test results, with medium roasted beans that were less difficult to grind, so not that many stalls. Similarly timed extractions are in bold.



All grinders except the Hario provided a similar taste profile and produced excellent espresso. The Hario was flatter and more bitter, but given the cost it's surprising that it can even produce workable grind for espresso.

Next up I plan to test for percentage of fines.

Assuming you are turning the crank by hand you are really fast, at least from my perspective. For me 180 RPM is kind of near the top in terms of rotation speed. I'm sure I can go faster but it would be really uncomfortable. My natural turn rate is about 120 RPM.

Or could a higher rotation rate be a natural result of doing lots and lots of hand grinder tests?

This is the avarage speed. In the last few seconds I usually grind much slower to reduce popcorning. I guess it means that the peak speed is somewhere around 200 RPM. This is what works well for me. Lower speed tends to increase the chance of stalling, most noticeable with light roasted beans.

Maybe that's it then, the roast level. I had a much lighter roast than usual recently and thought to myself that if this were my typical coffee I would buy an electric grinder.

What grinder are you using? If I had to use something like the K-Plus or K4 to grind light roasted beans I would give up and get an electrical grinder too. But with the slower grinders? I'm not so sure.

I have a Kinu M47 Phoenix.

The beans I was grinding weren't even really a "light" roast. They were just lighter, probably would be considered "medium" by many. And it's not like I'm adverse to the physical aspect of hand grinding. I really enjoy turning that crank. I just don't like the stuttering/stalling thing.

The coffee wasn't to my liking anyway. The bag promised milk chocolate, sugarcane, and cherries. Despite my best efforts the coffee I got tasted like celery and lemon juice. Maybe I don't know what I'm doing or maybe I just don't have the right palate for lighter roasts. But I think it was the coffee. It wasn't the first time I've had what I felt was a dud from this particular roaster. Half of it went down the sink, the rest into the compost bin.

For what I call medium the M47 does a great job (both with regards to taste and effort). IF the roast was indeed very light it could be difficult to impossible to extract well with that grinder though.