The 48 mm conical burr grinder is one of the key components of the xBloom Studio. With its 80 grind settings and adjustable speed, it promises precision worthy of a dedicated grinder. But does it deliver?
This machine was sent to me by xBloom. That said, my opinion remains completely independent: I say what I think, without sugarcoating it.
This article is part of a complete series on the xBloom Studio: overview, brewing modes, grinder and accessories.
Technical Specifications
| Specification | Detail |
|---|---|
| Burr type | Conical, stainless steel |
| Diameter | 48 mm |
| Number of settings | 80 |
| Gap between clicks | ~18.75 microns |
| Speed | Adjustable from 60 to 120 RPM |
| Measured retention | < 0.3 g |
Recommended Grind Ranges
The grinder covers a wide spectrum, from espresso to French press:
These settings are indicative and may vary depending on your coffee and preferences.
On paper, this adjustment range covers the entire spectrum, from espresso to French press. But as we'll see later in this review, the burrs have clearly been optimized for coarser grinds. The xBloom is a pour-over machine, and its grinder reflects that purpose.
Pour-Over Performance: Excellence
Pour-over is where the grinder shows its full potential, which makes sense, since that's precisely what it was designed for.
Grind Quality
The 48 mm conical burrs deliver remarkable particle consistency across the whole range of coarser grinds. I compared them visually with several dedicated grinders, and the distribution is excellent.
Here's the coffee and the recipe used for the test.
The result in the cup? Clarity of flavor worthy of the best grinders, with well-defined notes and an even extraction. Specialty coffees with fruity or floral profiles really shine.
I compared the xBloom's grinder with several of my high-end grinders: the Millab E01, the Millab M01 and the Timemore S3. For results in the cup, I place it between the Timemore S3 and the Millab E01: grind consistency, aromatic definition and a clean cup, all clearly high-end for pour-over. An impressive performance for a grinder built into an automatic machine.
Espresso Performance: Capable but Not Specialized
It's a question many people ask: can the xBloom Studio's grinder go fine enough for espresso?
The Short Answer: Yes
With its 80 settings and a gap of 18.75 microns between clicks, the grinder goes fine enough to produce a grind suited to espresso. I tested it with my espresso machine, and the results are convincing.
Aromatic Profile in Espresso
The result in the cup has a profile that's slightly more acidic than what you'd get from a dedicated espresso grinder. That makes sense: the conical burrs of the xBloom Studio are optimized for pour-over, which favors clarity and tangy notes.
The Magnetic Dosing Cup
A well-thought-out detail: the magnetic dosing cup supplied with the machine fits 58 mm portafilters perfectly. Transferring the grounds to the portafilter is clean, with no loss.
The xBloom Studio's grinder isn't a dedicated espresso grinder, but it does a respectable job if you want to make an espresso now and then. By comparison, my grinders fully dedicated to espresso give a more complete result in the cup: the Timemore S3 ESP, for example, delivers a denser extraction and a more defined profile. For daily espresso use, a dedicated grinder is still the better choice. But as a backup grinder, it gets the job done.
Retention: An Excellent Result
I measured the grinder's retention over several cycles:
| Measurement | Retention |
|---|---|
| Measurement 1 | 0.28 g |
| Measurement 2 | 0.31 g |
| Measurement 3 | 0.25 g |
| Average | < 0.3 g |
Less than 0.3 g of retention after grinding: an excellent result for a built-in grinder. The anti-static technology helps limit the buildup of grounds in the chute.
Rotation Speed: The Impact on Taste
An interesting feature: the rotation speed is adjustable between 60 and 120 RPM.
With conical burrs, you ideally don't want to grind too fast: the higher the speed, the more heat the friction generates, and heat degrades volatile aromas before extraction even begins. The 60 to 120 RPM range offered by the xBloom is therefore perfectly calibrated: these are the same speeds you reach when grinding by hand with a manual grinder.
Getting as close as possible to manual methods. Slow grinding at the speed of a hand grinder, controlled pours like a handcrafted pour-over: the xBloom automates without sacrificing what makes specialty coffee great.
Using an External Grinder
A feature that's often underestimated: you can disable the built-in grinder of the xBloom Studio, either from the app or directly on the machine by turning the adjustment dial after selecting the recipe.
The big advantage? You can brew on the machine with coffee from any other grinder. Grinders are a bit like lenses in photography: each has its own characteristics, its own rendering, its own specialty. Swapping grinders fundamentally changes the aromatic profile in the cup.
I use this option often myself, since I have quite a collection of grinders. It lets me brew with different grinders while keeping the recipe strictly identical.
This is how I test grinders on this blog: the xBloom standardizes the recipe and the extraction, and I change only the grinder. You can then clearly taste the aromatic differences from one grinder to the next, with a rigorously identical protocol every time.
Grinder Maintenance
Maintenance is simple and infrequent:
Regular Cleaning
- A quick brush (supplied) through the chute from time to time
- The anti-static technology limits buildup
Deep Cleaning
For a more thorough cleaning, you can use Puly Grind or an equivalent. Run a few grams through, then purge with coffee.
You can also disassemble the grinder for a complete cleaning. That said, having had the machine for about two months at the time of writing this review, I haven't done it yet: passive cleaning is enough for now.
Calibration
If you notice inaccuracy in the grind (coffee running too fast or too slowly at the same setting), the machine offers automatic calibration, accessible from the app.
Conclusion
The grinder in the xBloom Studio fulfills its main mission perfectly: producing a grind that's excellent for pour-over.
Its 80 settings, low retention and adjustable speed make it a quality component that holds its own against dedicated grinders. The espresso option, while not optimal, adds welcome versatility.
It's one of the things that convinced me the xBloom Studio offers excellent value for money: the grinder alone would be worth $390-450 as an equivalent standalone.
- 80 fine settings: 18.75 microns per click
- Retention < 0.3 g: excellent for a built-in grinder
- Adjustable speed from 60 to 120 RPM
- Pour-over results comparable to dedicated grinders
- Compatible with an external grinder
- A complete cleaning requires disassembly
Further Reading
This article is part of a series on the xBloom Studio:
xBloom Studio: Why This Pour-Over Machine Won Me Over
xBloom sent me their coffee machine. But honestly, if they hadn't, I think I would have ended up buying it myself. Here's why.
Read the article →
xBloom Studio: Full Review of the Pour-Over Machine
Discover our complete review of the xBloom Studio, an all-in-one automatic coffee machine combining grinder, scale, and brewer. With its 80 grind settings and three brewing modes, it promises specialty coffee worthy of a barista.
Read the article →
