Bests & Worsts Reviews from Amazon

I was frustrated by how slow this was, especially with larger beans. It turns out to be a copy of the Hario Coffee Hand Grinder Skerton, but the actual grinding mechanism has an inferior design, such that it takes twice as long to grind the same amount of coffee as the Hario. The prices are almost the same, so it doesn't make any sense to buy this instead of the Hario. After being frustrated by how slow it is, I bought the Hario. Before returning this one, I compared the two by setting them to the same grind (set with a boxboard spacer in the grinding mechanism), and then cranking the crank 200 revolutions and weighing the grounds I got from that. I got 25 g from the Cuissential, 50 g from the Hario. The design has two problems that make it slow: One is that there is a three-blade "propeller" just above the grinding mechanism, presumably to help guide the beans in. But the grinding blades have five channels. That means that only one of the channels in the grinding mechanism lines up well with the opening in the three-blade propeller. Two are about half blocked, one is only a little blocked, and one is completely blocked. If you have small beans, they might still get in the partly-blocked channels, but with big beans, you might only effectively use one of the five channels, or maybe two. Edit: You could remove the propeller and that may help some, but both I and people commenting on this review haven't found that helps much. I've added a photo with the Hario on the left and the Kuissential on the right. You can see that the sprial feed part is is longer on the Hario. That may be another reason for the difference in performance. I should mention that their customer service rep was very friendly and responsive, even though he ultimately had no real solution other than courteously accepting the return and providing a refund.