What does your La Marzocco machine do in Grind-by-Sync?
In traditional bar work, the espresso machine and the grinder know nothing about each other. The grinder grinds, the machine brews, and the barista watches the time and adjusts the grinder when the espresso starts running faster or slower. At the peak this is easy to miss.
In Grind-by-Sync the espresso machine becomes a source of data. After every espresso it records the extraction time and sends it to the grinder over Wi-Fi and both brands' cloud. On the next grind, the grinder compares this time with the recipe and moves the burrs: finer when the espresso runs too fast, coarser when it runs too slow.
The system does not judge taste. It holds the parameters the barista set in the recipe. The barista decides how the espresso should taste, and Grind-by-Sync helps keep that result throughout the day.
Recipe and adjustment: how the grinder makes its decision
The reference point is the recipe saved in the grinder: the coffee dose in grams, the beverage amount and the target extraction time. The barista sets it once, when the espresso tastes the way it should.
The grinder does not react to a single coffee. It takes the average of the last few extractions, so one crookedly tamped espresso doesn't shift the settings. If the time stays on recipe, the grinder may change nothing for a whole shift. When the coffee changes, the temperature in the venue shifts or the burrs heat up at the peak, it adjusts the setting every few coffees.
The adjustments are small, and the grinder knows the burr position to within 0.001 mm. Mechanical precision is not a guarantee of taste, though: the machine passes on the time, not a verdict on the espresso.
AV or ABR: which machine version to choose for this system?
When choosing a La Marzocco machine for Grind-by-Sync, it is not only the model that matters but also how the machine ends the espresso. We describe the differences between versions in detail in the guide AV, ABR, EE, MP: La Marzocco machine versions.
| Machine version | How it ends the espresso | What it gives you with Grind-by-Sync |
|---|---|---|
| AV | after a programmed volume of water | sends the extraction time, the grinder adjusts the grind; a good choice for most cafés |
| ABR | on reaching a beverage weight or ratio (drip tray scales) | the grinder controls the dose, the machine the beverage weight, and time, i.e. the grind, remains the only variable; the most complete pairing |
The ABR version has drip tray scales and ends the espresso when the set beverage weight is reached. The grinder controls the dose by weight, the machine controls the weight in the cup, and time remains the only variable. That is exactly the parameter Grind-by-Sync adjusts, which is why ABR gives the most complete pairing.
Is ABR always better? No. The AV version also works with the system and is more than enough for most cafés. We explain when paying extra for scales makes sense in the guide ABR drip tray scales or AV dosing.
Which La Marzocco machines connect to the grinder?
Grind-by-Sync works with La Marzocco machines in the AV or ABR versions:
Already have one of these models, but an older unit without connectivity? You don't have to replace the machine. According to Prima Coffee, older units can be retrofitted with an IoT kit from La Marzocco. Before buying a grinder, check the exact model and version of your machine, because the name alone doesn't tell you whether it is AV or ABR.
If your machine is not on this list, the Mahlkönig Sync Scale, shown at HostMilano in October 2025, will connect it to the system. It sits under the cup and sends the espresso time and weight to the grinder.
Which Mahlkönig grinder to pair with La Marzocco?
- E65W GbS: 65 mm burrs, grind by weight. According to Prima Coffee, the dose holds to within 0.1 g. For most cafés.
- E80W GbS: 80 mm burrs, grind by weight, for venues with very high traffic.
- E65T GbS and E80T GbS: the same grinders in a time-dosing version. They also work with the system, but the W versions with scales are the most precise.
An important point for continuity: without a connection the grinder still grinds by weight, it just doesn't adjust its settings. Losing the internet doesn't stop the bar. We describe how to choose the grinder itself for your venue's traffic in the guide Espresso grinder for a café.
How to start working with Grind-by-Sync
- Dial in a new coffee by hand first, as always. The system corrects small deviations; it doesn't set the grinder up from scratch.
- When the espresso tastes right, save the recipe in the grinder: dose, beverage amount and time.
- Pair the machine with the grinder in the Mahlkönig Sync and La Marzocco apps. In the Mahlkönig app you can send a recipe to several grinders at once and see statistics and service alerts.
- Changing the dose or the beverage amount? Save a new recipe. The system is based on time, so the old recipe doesn't fit the new parameters.
We combine the rollout of a new machine and grinder with team training. We describe the programme in the guide Barista training for a new espresso machine.
What Grind-by-Sync won't do for the barista
The machine measures time, but it doesn't know why the espresso ran faster. If the coffee in the basket is unevenly distributed or tamped crooked, water flows through the gaps, which is channeling. In “The Professional Barista's Handbook”, Scott Rao describes how this uneven flow gives uneven extraction and worse taste. The grinder will then read a fast espresso as too coarse a grind and may adjust in the wrong direction.
That is why even puck preparation matters more here than ever. At SAINT, a new specialty café in Warsaw, the bar runs a La Marzocco, a Mahlkönig grinder and a PUQpress automatic tamper under the grinder. It is a good example of dividing the work: the tamper takes care of even tamping, and grind adjustment is a separate task that the grinder takes over in Grind-by-Sync.
- Wi-Fi. The connection goes through the cloud, so you need a stable signal at the bar.
- Recipe. The system holds the parameters you set, but it doesn't invent new ones.
- Coffee and cleanliness. Stale coffee or a dirty group will give bad espresso however well the grinder hits the time.
Should you plan for Grind-by-Sync when buying an espresso machine?
If you are choosing a new La Marzocco machine, it is worth thinking about it straight away: pick a model from the compatible list, decide on the AV or ABR version and choose an E65W GbS or E80W GbS grinder. We show the differences between models in the comparison of Linea Classic S, Linea PB, KB90 and Strada.
Venues that make a lot of coffee with different people behind the bar gain the most: high-traffic cafés, chains and hotels with a lobby bar. In a small café with one experienced barista, an ordinary grind-by-weight grinder is also enough, and the system can be switched on later, because GbS grinders work on their own.
We will match a La Marzocco machine and a Mahlkönig grinder for Grind-by-Sync.
frequently asked questions
Will Grind-by-Sync set up the grinder for a new coffee by itself?
No. You first have to dial in a new coffee by hand and save the recipe. After that the system adjusts the grind based on the time of the following extractions.
Does every La Marzocco espresso machine support Grind-by-Sync?
No. The system works with Linea Classic S, Linea PB, Linea PB X, GB5 S, GB5 X, KB90 and Strada S in the AV or ABR versions. Older units without connectivity can be retrofitted with an IoT kit, and other machines can be connected through the Mahlkönig Sync Scale.
Does Grind-by-Sync work without the internet?
Grind adjustment needs a connection. Without the internet, the E65W GbS and E80W GbS grinders still grind by weight, but they don't change their settings.
Does the grinder change the grind after every espresso?
No. It looks at the average of the last few extractions. It may adjust every few coffees or change nothing for a whole shift.
AV or ABR for Grind-by-Sync?
Both versions work. ABR stops the espresso by beverage weight, so time remains the only variable and this pairing is the most complete. AV stops by volume and is more than enough for most cafés.
Will Grind-by-Sync replace the barista?
No. The system keeps an eye on extraction time, but it does not judge taste or puck preparation. Uneven tamping causes channeling and can lead to wrong adjustments.
read also
- Linea Mini or GS3? Which one for your home?
- Which espresso machine for an office? Does a traditional one make sense?
- Linea Micra or Linea Mini? Which one for your home?
- How to make milk drinks faster in a café
- Espresso machine for a roastery or showroom: how to show off your coffee
- 10 mistakes when buying a café espresso machine (and how to avoid them)
- Espresso machine for a bakery or patisserie: selling coffee alongside your bakes
- Is a more expensive café espresso machine worth it?
- New espresso machine in your café: a barista training plan for the first month
- Espresso grinder for a café: on-demand or doser, and how many you need
- ABR drip tray scales or AV dosing? When the extra cost pays off
- Espresso machine service: what it covers, how often, and when to call a technician
- Café espresso machine leasing: lease, rent or buy?
- La Marzocco in Warsaw: Tekla, Doza and Wandal
- Specialty café: which espresso machine to choose? What a specialty café needs
- Opening a café? An equipment plan, step by step
- Dual boiler, saturated group, independent boilers: what they change in the cup
- When to replace your café espresso machine? 5 signs
- Water for espresso machines in venues: hardness, filtration, boiler protection
- Espresso machine cleaning and backflush: a schedule for your team
- Espresso machine for a restaurant or hotel: what to look for
- Which espresso machine for a café? A guide to La Marzocco machines
- Linea Classic S, Linea PB, KB90 or Strada? A comparison
- AV, ABR, EE, MP: what La Marzocco machine versions mean
- Preparing your venue for an espresso machine: power, water, drain
- How many groups does your venue need?