Single-dose espresso grinders thrill us. Accordingly, our review of the Niche Zero was very positive. But the Niche, even before Brexit, digs a deep hole of a good 800 euros into your wallet. We wished for similar performance for less money. And to anticipate: the G-Iota, which is also offered as DF64 in many places, fills exactly this gap. The DF64 costs half the price of the Niche Zero, but its performance is nothing to hide.
To the current review of the DF64 Generation 2.
In our review, we examine the grinder in all its facets, offer a few tips, and even venture a first comparison with the 23 other espresso grinders we are currently testing. Here's the comparison with grinders in the same price range.
In the meantime, we have published an upgrade video for the G-Iota. We tried out several things. Among other things, we installed SSP Multipurpose burrs, which do a really good job. This makes the DF64 even better.
For Austria and Germany, Bohnendealer* is the importer of the G-Iota. Unfortunately, there is no official importer in Switzerland.
Single dosing – what is it?
Espresso grinders are currently experiencing their second evolution, which has now also reached the home market. The first evolution was the step from "storage hopper" or "dispenser" to direct grinding or "grind on demand." Instead of pre-grinding larger quantities of coffee and storing it in a dispenser, coffee was ground directly into the portafilter. This was a first step towards more freshness and less oxidized coffee.
Today, we are going through the second evolution, with the step to single-dose grinders. Because previously, a larger part of the coffee remained exposed to oxygen and light in the bean hopper. The single-dosing principle is permeating the market, and it works like this: a home barista weighs the desired amount of coffee, places it into the input area, and grinds it directly into the portafilter.
This makes it possible to switch coffees. For guest A, a decaf can easily be brewed, while guest B prefers a fruity espresso. The coffee stays fresh longer because it is stored in the perfect container. For the home barista, weighing the coffee reveals the relationship of the brewing ratio, and the possibility of experimenting with recipes opens up.
A single-dose grinder must be able to do this:
The grinder should have no retention and eject all the ground coffee.
The brewing recipe must be easily adjustable, and the grind size, even after adjustment and returning to the same marked area, should yield the same particle distribution.
In short, consistency and precision are important!
The bellows of the DF64 ensure that the grinder has no retention.
DF64 as a single-dosing grinder
The DF64 fulfills the necessary criteria for a good single-dosing grinder very well. It uses some aids, such as the bellows, but in the end, the grinder achieves its goal.
If the DF64 is used without the bellows, it has a retention of 1.5 grams of coffee. While this is a good result compared to many traditional grinders, it is unacceptable for a single-dosing grinder. However, by using the bellows, the retention can be reduced to almost 0 grams. We recommend that after grinding the main amount of coffee, you give a few puffs with the bellows to remove any remaining coffee powder from the area behind the flapper. Caution: this can result in a powerful puff that can also scatter some coffee powder on the table. However, we were usually able to avoid this by gently puffing. This reduces the residue in the grinder (retention or grind retention), and, for example, the 18 grams of coffee put in are consistently ground out again.
The grinder also impressed us with its precision. It was easy for us to adjust the grind size and return to the same grind setting. In fact, the grinder lacks a good grind size marking. Creative minds have developed marking pointers for 3D printers that work well and can also be ordered, for example, from portals like Etsy*.
A corresponding update can improve the grinder even further or make it easier to use. However, we had no problems setting the grinder back to the same grind size. In fact, the grinder was more precise when adjusting and readjusting than many other grinders in the test series.
Thus, we can attest to the DF64 or G-Iota everything that makes a good single-dosing espresso grinder!
Espresso performance of the DF64
The espressos from the DF64 tasted good to us. They were well-balanced, and different nuances could be well-emphasized. The particle distribution of the grinder was solid average.
Espresso data (T4):
- X50: 318.30 Micron
- Fine peak: 20.78 %
- Main peak: 247.58 Micron
Operation of the DF64/G-Iota
We already covered the operation of the DF64 in the chapter on single-dosing capability. Fundamentally, the grinder can be adjusted precisely and easily. The large grind adjustment wheel turns very smoothly and allows for stepless adjustment. The large diameter provides a slow translation for effective grind adjustment. This is very positive, in contrast to grinders like the Eureka Specialità, where the small adjustment wheel often overshoots the mark.
The grinder has no other adjustment options. There is an on and off button. That's it.
The alignment of the espresso grinder is not part of the classic "adjustment" and operation scope. Some users report that their DF64 was delivered with burrs that were not perfectly aligned. As a result, the ground coffee has a less precise particle distribution, and the burrs also dull faster. The position of the burrs can be checked and adjusted independently. We will make a video about this. However, under the keyword Grinder Alignment, there are already some instructions available online. On our DF64 model, the burrs were perfectly aligned.
When using the bellows, we advise careful and controlled pressing so that the grind size does not change.
Side view of the G-Iota with a transparent dosing cup that fits directly onto the portafilter.
Size, weight, and appearance
Elegant, slim, and heavy - that's how the G-Iota stands next to our Decent Espresso. It is available in various color patterns. We bought and tested a black and a white model (like all grinders, we bought these grinders ourselves for testing purposes). The grinder is one of the heavier grinders in the price segment up to 500 Euros. The grinder weighs 13 kilograms, making it very stable and solid. 30 mm height, 130 mm width, and a depth of 225 mm create a harmonious picture.
A transparent dosing cup is supplied with the grinder. The dosing cup fits well into the portafilter holder. Our cup got a small crack when tapping it out. Benjamin and Michel were divided on their assessment of the cup. While Michel would switch the cup for a metal one, Benjamin appreciated the transparent design. The visibility is especially interesting for learning and training purposes, as it clearly shows how the coffee powder distributes itself in the portafilter.
Not only does the dosing cup fit into the holder, but also all common portafilters from companies like Rocket, La Marzocco, or Slayer. For portafilters with larger side flanges, there is wear and tear on the rubber holders. However, these can be easily replaced.
Conclusion on the DF64 - G-Iota
The G-Iota is a really good grinder that convinced us in almost all categories in our test. Only in terms of speed is the grinder among the slower ones, with an output of only 19.1 grams in 10 seconds.
The noise level of the grinder is in the mid-range at 83.2 decibels. Operation is smooth and very precise. The bellows reduce retention to 0. This makes the grinder very good not only as a single-dosing grinder.
In terms of price-performance, the G-Iota is convincing with a purchase price of around 400 Euros. As you can also see from our video: we are very impressed with the DF64. A really good espresso grinder and a very interesting choice as a single-dosing grinder.
And that's not all: if you want to further improve the grinder, you can achieve even better grinding results by opting for 64er SSP burrs. Whether this is necessary and whether we can detect the difference in a blind tasting, we will provide you with the results and a video later. A direct comparison with Niche Zero and Eureka Single Dose is also planned.
Upgrade Video for the DF64 G-Iota
► SSP Red Speed Burrs at Bohnendealer*
► G-Iota Grind Indicator on Etsy*
► Slanted Improved Dosing Cup Holder for DF64, G-IOTA on Etsy*
► G-Iota Dosing Cup Holder 51 mm on Etsy*
*This is a commission link. If you order through this link, it won't cost you more. However, we will receive a small commission. This helps us to buy more test material and publish new tests. Thank you in advance! We also refer to a shop here that we know well and from which we know that it provides good service.
