OTTO SIENA 85MM Timer Dosing Grinder

Bigger 85mm Flat Burrs for More Confident Light-Commercial Espresso Grinding

The OTTO SIENA 85MM Timer Dosing Grinder is designed for cafés, bakeries, restaurants and F&B operators who want a more substantial light-commercial grinder with 85mm flat burrs, stepless micrometric adjustment, timer dosing and a 1.2kg bean hopper.

It is recommended for light-commercial use with coffee consumption of up to approximately 2kg per day, making it suitable for businesses that need a proper commercial grinder but do not necessarily require a very high-volume setup.

Designed in Florence, Italy, the SIENA 85MM is particularly appealing to operators who value larger burrs, precise grind control and repeatable café workflow.

Best For

The OTTO SIENA 85MM is best suited for:

• Small cafés

• Bakeries and dessert shops

• Restaurants with a dedicated coffee menu

• Boutique hotels and hospitality concepts

• F&B businesses adding a more serious espresso programme

• Light-commercial coffee counters

• Operators using one main house coffee throughout service

• Businesses with coffee consumption up to approximately 2kg per day

Why Choose the OTTO SIENA 85MM?

85mm Flat Burrs

The standout feature is the 85mm flat burr set.

A larger burr platform gives the grinder more grinding surface area and creates a more substantial commercial platform for repeated espresso preparation.

For buyers comparing grinders, the 85mm burr size is especially relevant if you want a grinder that feels more serious than smaller light-commercial models while still remaining within a moderate-volume operating range.

Stepless Micrometric Regulation

The SIENA 85MM uses Stepless Micrometric Regulation, based on a patented Conti Valerio srl system.

Instead of fixed click positions, the grinder provides effectively infinite adjustment points.

This gives you much finer control when dialling in espresso and allows small changes as:

• coffee beans change

• humidity changes

• extraction time shifts

• recipes are adjusted

For a café, this matters because espresso does not stay perfectly dialled in all day without adjustment.

Timer Dosing for More Repeatable Service

The grinder uses timer dosing to help produce a more repeatable dose during service.

This is useful when:

• several staff use the same grinder

• the café uses one main house coffee

• speed and consistency matter

• you want to reduce manual guesswork

A repeatable dosing workflow can make espresso preparation easier to standardise across the team.

1.2kg Bean Hopper

The 1.2kg hopper is suitable for a working commercial coffee station using one primary bean.

It reduces the need for constant refilling and suits a café-style hopper workflow better than a single-dose grinder.

What Does “Up to 2kg Per Day” Mean?

The SIENA 85MM is recommended for light-commercial use with coffee consumption of up to approximately 2kg per day.

That figure should not be treated as a guaranteed number of drinks.

What matters more is:

• how concentrated your busy periods are

• how many espresso orders arrive together

• your dose size

• how many staff use the station

• what percentage of your menu is coffee

• whether the grinder is used continuously or intermittently

A café using 2kg evenly throughout the day has a different workflow from one trying to use most of it during a short morning rush.

Grinding Productivity

The grinder is rated at approximately 1–3g per second, depending on grind setting and coffee.

Actual performance will vary with:

• grind fineness

• bean density

• roast level

• dose size

For light-commercial espresso service, this provides a practical grinding speed while maintaining fine adjustment control.

Why Choose the 85MM Version Instead of a Smaller Grinder?

The main reason is the larger burr platform.

The SIENA 85MM is worth considering if you want:

• a more substantial grinder

• larger 85mm flat burrs

• commercial hopper workflow

• precise stepless adjustment

• timer dosing

• more confidence in repeated café use

If coffee is an important part of your business and you prefer to invest in a larger burr system from the start, the 85MM model is the stronger proposition.

Who Should Buy the OTTO SIENA 85MM?

Choose this grinder if:

• coffee is an important part of your F&B operation

• you want 85mm flat burrs

• you prefer hopper-based commercial grinding

• you use one main house coffee

• you want timer dosing for a more repeatable workflow

• you need precise stepless grind adjustment

• your coffee usage fits within a light-commercial operating range

Who Should NOT Buy It?

The OTTO SIENA 85MM may not be the right choice if:

• you need a true high-volume grinder for a very busy café

• your daily coffee consumption regularly exceeds the recommended light-commercial range

• you frequently change between several beans

• you prefer single-dose grinding

• you are buying for occasional home use

• your counter has limited vertical space

At 680mm high, this is also a relatively tall grinder, so counter clearance should be checked before purchase.

Recommended Pairing

The OTTO SIENA 85MM is suitable for pairing with:

• semi-commercial espresso machines

• 1-group commercial machines

• compact 2-group commercial machines

• light-commercial café setups

• espresso bars using one main house bean

The grinder should be matched to the actual machine, menu and workflow rather than chosen only by burr size.

Key Specifications

Brand: OTTO
Model: SIENA 85MM
Product Type: Timer Dosing Coffee Grinder
Burr Size: 85mm Flat Burr
Burr Type: Hardened Burrs
Adjustment: Stepless Micrometric Regulation
Grinding Productivity: Approx. 1–3g/s
RPM: 1350 RPM
Power: 320W
Bean Hopper Capacity: 1.2kg
Recommended Usage: Light commercial, up to approximately 2kg coffee per day
Weight: 10.5kg
Dimensions: W262mm × H680mm × D235mm
Design: 100% designed in Florence, Italy

What Problems Does the OTTO SIENA 85MM Solve?

You Want Finer Espresso Adjustment

The stepless micrometric system lets you make very small grind changes instead of being limited to fixed settings.

Your Home Grinder Is No Longer Suitable

The 85mm burrs, commercial hopper and timer-dosing workflow are better suited to repeated café service.

You Want Easier Dose Repeatability

Timer dosing helps make day-to-day espresso preparation more consistent.

You Want a Larger Burr Platform Without Jumping Straight to High-Volume Equipment

The SIENA 85MM provides a stronger commercial-style grinder while still being positioned for light-commercial usage.

Why Buy the OTTO SIENA 85MM from Biji-Biji?

Biji-Biji helps customers choose coffee equipment based on how the business actually operates, not simply on the biggest burr size or headline capacity.

We can help you consider:

• your espresso machine

• menu mix

• peak-hour workflow

• daily coffee usage

• whether you use one house coffee or multiple beans

• counter space

• budget

The goal is to recommend a grinder that fits your operation, rather than simply selling the largest model available.

Need Help Choosing?

Not sure whether the OTTO SIENA 85MM is the right grinder for your setup?

Tell us:

• which espresso machine you use

• what drinks you serve

• how busy your peak periods are

• whether you use one main bean or several

• how important coffee is to your overall business

and the Biji-Biji team can help you compare suitable grinder options.

WhatsApp Biji-Biji and ask about the OTTO SIENA 85MM Light Commercial Coffee Grinder.