Rossi RR45: A Reliable Commercial Grinder Worth Knowing About
The Rossi RR45 is a commercial coffee grinder that's been a workhorse in cafes and small roasteries for years. Built in Italy, it sits in that mid-range commercial category where you get serious grinding performance without the price tag of a Mazzer Super Jolly or Mahlkonig K30. If you're outfitting a small cafe, setting up a home setup with commercial-grade equipment, or eyeing one on the used market, here's what you should know.
I've used the RR45 in a friend's cafe and spent time with one at a local roastery. It's a straightforward, dependable machine that does what it's designed to do. I'll cover the build, burr performance, adjustment system, and how it holds up compared to other commercial grinders in its class.
Build and Construction
The RR45 is built like most Italian commercial grinders: heavy, metallic, and designed to sit in one spot for years. The body is die-cast aluminum with a standard commercial finish. It weighs about 9 to 10 kilograms, so it stays planted on the counter even during heavy use.
Motor and Drive
The grinder runs a direct-drive motor that spins the burrs at around 1,400 to 1,600 RPM. This is a standard speed for commercial flat burr grinders. The motor is quiet by commercial standards, with a steady hum rather than the screaming whine you hear from some cheaper high-RPM grinders.
Power consumption is moderate. The motor handles continuous grinding sessions without overheating, which matters in a cafe environment where you might grind 20 to 30 doses in an hour during a morning rush.
Hopper
The stock hopper holds about 600 grams of beans. That's enough for a small cafe that goes through moderate volume. Larger cafes might find themselves refilling more often than they'd like, but for home use or low-volume commercial settings, it's plenty.
The hopper is clear plastic, so you can see the bean level at a glance. It seats securely on top of the grinder body and includes a shut-off slide for swapping beans without making a mess.
Burr Set and Grind Quality
The RR45 uses 45mm flat burrs, which is where the model name comes from. These are smaller than the 64mm burrs found in higher-end commercial grinders, but they're perfectly adequate for moderate-volume espresso grinding.
Espresso Performance
For espresso, the 45mm flats produce a respectable grind. The particle distribution is tight enough for consistent 25 to 28 second shots with good body and crema. I pulled dozens of shots on the RR45 during my time with it, and the results were reliably good.
The smaller burr size means slightly slower grinding compared to a 64mm machine. Expect about 5 to 7 seconds per 18-gram dose, versus 3 to 4 seconds on larger-burr grinders. For a small cafe doing 50 to 100 drinks a day, this difference is noticeable but manageable. For home use, it's a non-issue.
Grind Retention
The RR45 retains about 2 to 4 grams of ground coffee between doses, which is typical for commercial grinders with standard chutes. This isn't a single-dose grinder. It's designed for a cafe workflow where you purge a small amount before each dose and keep the hopper loaded throughout the day.
If you're considering it for home use with single-dosing, you'll need to account for this retention. Running a few grams of purge beans before each dose wastes some coffee but ensures freshness. Some home users modify the chute with a shorter exit path or 3D-printed parts to reduce retention.
For home-focused grinders with lower retention, our best coffee grinder roundup covers single-dose options from brands like Niche, Lagom, and others.
Adjustment System
The RR45 uses a stepless collar adjustment around the burr housing. You turn the collar to move the burrs closer together (finer) or farther apart (coarser). The adjustment is smooth and responsive, with small turns producing proportional changes in grind size.
Dialing In
Dialing in espresso on the RR45 is intuitive. Small quarter-turn adjustments change shot time by 2 to 4 seconds, which gives you good control without overshooting. The collar stays put once set, and I didn't experience any drift during extended grinding sessions.
Range Limitations
The 45mm flats are optimized for espresso. You can adjust coarser for drip or filter, but the grind consistency drops off at coarser settings. This is a single-purpose espresso grinder, not a multi-use grinder. If you need to grind for both espresso and batch brew, you'll want a separate grinder for filter or a different machine altogether.
Noise and Heat Management
At 1,400 to 1,600 RPM, the RR45 generates moderate noise. It's quieter than budget grinders that spin at 10,000+ RPM, but louder than a hand grinder. In a cafe environment, it blends into the background. At home, it's noticeable but not obnoxious.
Heat management is adequate for low to moderate volume. The motor and burrs stay cool during typical home use (5 to 10 doses per day). In a busy cafe grinding continuously, the burrs will warm up. This can affect grind size slightly as metals expand, requiring minor adjustment during peak hours. Experienced baristas know to check their shots after extended grinding periods and nudge the adjustment if needed.
Buying a Used RR45
The RR45 shows up on the used market regularly as cafes upgrade to newer equipment. This is where the grinder becomes an interesting value proposition.
What to Check
- Burr wear: Look at the burr edges. Sharp, well-defined edges mean plenty of life left. Rounded, smooth edges mean the burrs need replacing. Replacement burrs are affordable and easy to install.
- Motor sound: Listen for grinding or rattling in the motor when running empty. A healthy motor sounds smooth and steady.
- Adjustment collar: Make sure the collar turns smoothly without sticking or grinding. Worn threads can cause drift.
- Doser condition (if applicable): Older models with dosers should have springs and paddles intact. Many users remove the doser and add a direct chute modification.
A used RR45 in good condition can be found for $100 to $300, which is remarkable value for a commercial grinder. Compare that to a new Niche Zero at $500 or more, and the RR45 becomes a serious budget option for home espresso.
How It Compares
RR45 vs. Mazzer Super Jolly
The Super Jolly has larger 64mm burrs, a more powerful motor, and better grind consistency. It's a step up in every measurable way. But it also costs significantly more, both new and used. The RR45 gets you 80% of the performance at half the price.
RR45 vs. Eureka Mignon
The Eureka Mignon series targets home users with 50mm flat burrs, low retention, and a compact footprint. For home use, the Mignon is more practical. The RR45 is bigger, louder, and designed for a different workflow. But if you find an RR45 for $150 used, the grind quality per dollar is hard to beat.
For a broader comparison of current grinders, our top coffee grinder list covers both home and commercial options.
Frequently Asked Questions
Is the Rossi RR45 good for home use?
It can work at home if you have the counter space and don't mind the size. The grind quality is excellent for espresso. The main drawbacks for home use are retention (2 to 4 grams), noise, and the larger footprint. Single-dosing requires a purge routine.
How often do the burrs need replacing?
At home volumes (under 500 grams per week), the 45mm flats should last 3 to 5 years. In a cafe grinding 2 to 5 kg per day, burr life is closer to 12 to 18 months. Replacement burrs are widely available.
Can I convert the doser model to a doserless setup?
Yes, and many people do. You can remove the doser mechanism and attach a direct chute or funnel. There are 3D-printed modifications available from the home barista community. This reduces retention and modernizes the workflow.
Where are Rossi grinders made?
Rossi grinders are manufactured in Italy. The company has been making commercial coffee equipment for decades and has a strong reputation in the European cafe market.
A Solid Workhorse at the Right Price
The Rossi RR45 isn't flashy, and it doesn't have the name recognition of a Mazzer or Mahlkonig. But it grinds espresso well, it's built to last, and it's available at prices that make high-quality grinding accessible. If you find one used in good condition, it's one of the best values in espresso grinding. Inspect the burrs, listen to the motor, and you could have a commercial grinder on your counter for the price of a budget home unit.