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Home » Acaia Lunar: How Accurate Is The Acaia Lunar?

Acaia Lunar: How Accurate Is The Acaia Lunar?

Are you using a French press? Espresso machine? Pour-over? Another coffee brewing method? The most important thing is getting a consistent ground-coffee-to-water ratio. After all, brewing coffee is both an art and a science.

But does it sound strange when I say espresso scale with Bluetooth connectivity? At first glance, it might sound a bit odd. But once you hear the story, you will no longer have doubts. There are many reasons why we decided to try the Acaia Lunar scale; one of them is certainly this cool connectivity.

We tested Acaia Lunar’s precision, speed, power, and accuracy. So, is spending hundreds of dollars on a coffee scale worth it? You’ll have to read this Acaia Lunar scale review to find out.

Summary: The Acaia Lunar

  • Extremely fast at 20ms response time
  • Battery lasts for around 20 hours thanks to the micro USB charging
  • Heat-resistant silicone pad preserves the scale from scratches and damages

Very accurate, extremely slim profile, and is a joy to use.

– Customer review

Acaia Lunar Scale Review

Acaia Scales were launched as a Kickstarter project in 2013 and quickly rose to the top of the coffee scale world. The Acaia team developed beautiful kitchen scale designs, and their products are famous for accuracy and high price tag.

Using a kitchen scale can make a world of difference…. all inconsistency is put right to bed.

You can’t eyeball the amount of coffee you use, but you need to be precise. Moreover, measuring coffee by grams is much more precise than measuring by scoops (1). Plus, having a consistent amount of grinds each time you make coffee lets you focus on other important factors, such as water temperature, brewing time, grind size, and more (2). This is why you need the best espresso scale.

Here’s how the Acaia Lunar coffee scale faired when we trialled this product.

Acaia Lunar Scale Review
  • Precision
  • Size
  • Style
  • Special Features
Acaia Lunar Scale

Precision – 5/5

Drawing from our experience, precision makes or breaks a coffee scale. Ideally, you want a coffee scale that lets you brew accurately and consistently. So, how accurate is the Acaia Lunar?

The scale’s precision depends on the sensitivity of the weight sensor and its responsiveness. We’re happy to report we don’t have any complaints about the Acaia Lunar’s precision. This scale has a maximum load capacity of 2kg, and minimum commercial-grade accuracy can measure within 0.1 g to 0.01 g.

Acaia Lunar is very sensitive to changes in weight and detects even weight loss to evaporation.

However, you can adjust the sensitivity. Espresso has the shortest brew time compared to other coffee drinks, and even a short lag affects how accurate your extraction is. This espresso scale has a 20 ms response time, which is incredibly fast and means you can weigh your shot yield accurately.

Overall, the precision and rapidly fast response time make the Acaia Lunar a great espresso scale, both for personal and commercial use.

Size – 4/5

Acaia scale Lunar measures 105 mm x 105 mm with a height of 15 mm. It weighs approximately 270 g. The small size (and extremely accurate precision) makes it a perfect espresso scale. It fits very well on the drip tray of most espresso machines. Plus, it’s compact, so you can take it while traveling.

Compared to the Acaia Pearl 2021 scale, the Lunar isn’t aimed at manual brewing. For example, you can fit a Chemx or a V60 on the Acaia Pearl. However, if you do so on the Lunar, you’ll struggle to read the display.

Note: You can buy a weighing plate separately. The plate fits on top, giving you more room for weighing a portafilter or fitting two cappuccino cups.

Style – 4.5/5

All Acaia scales have a sleek and modern design. In fact, it reminds us of sleek Apple products, from the packaging to the design. The scale is minimalistic and elegant no matter which colours you choose: black, white, or silver.

Acaia espresso scale is made of anodized aluminium — aluminium that’s been treated with an electrochemical process to develop a strong finish (3). This makes it durable, and you can use it for years to come.

It has an inverted design, which protects the scale’s interior. The weighing plate folds down over the weighing tray. Essentially, this is an upside-down scale. Moreover, it keeps the scale water-resistant. All electronic parts are coated with a water-resistant spray, which is very handy; you don’t have to worry about spilling your coffee or water over it.

The scale comes with:

  • A 100g calibration weight
  • A non-slip and friction-reduced strip for the bottom
  • Two friction-reduction protective strips
  • A heat-resistant pad
  • USB charging cable

Note: After conducting experiments with it, we found the scale slippery because of the anodized aluminium.

You have to be extremely careful when placing a metal portafilter on this scale.

A small careless movement, and it’ll slide off. So, we were glad to find out Acaia developers thought of how to address this and included the pad. Put the rubber mat on the scale and flip it however you like. The mat helps you prop the portafilter on the scale without sliding off.

For some people, sketches that can ruin the product’s aesthetic are inadmissible. Others think maintaining a perfectly glossy and clean machine makes no sense. In other words, it’s only important that the machine is fully functional. This espresso scale fits in both groups: it’s functional and has sets of crucial strips to avoid scratches. Whether you want to prevent sliding or scuffs, these sets got you covered.

Special Features – 5/5

If the world of coffee scales had a hierarchy, Acaia Lunar would be on top of it. This scale has a wide range of unique features which justify its high price:

  • Real-time flow indicator: Gives flow rate data in real time. This is helpful for noticing issues such as channelling.
  • Tare-save feature: You place the vessel you’re using for coffee dosing, select Tare Save, and the scale subtracts the container’s weight and shows the net weight. The result is a smoother and faster workflow.
  • Rechargeable Lithium-ion battery: The battery has a life of 30 to 40 hours. To save battery life, you can program the scale to turn off in 5, 10, 20, 30, or 60 minutes. If you plan to use the scale at home, you’ll go weeks without recharging.

Brew Modes

Before we dive into the brew modes, you must get familiar with the button functionality. Both buttons are multifunctional, meaning they can be tapped, pressed, or held, and each mode requires a different approach. For example, in the second mode you press the timer only once. Next, you must hold the button if you want to switch between modes. And if you want to turn off the scale, just double-tap the button on the left.

The modes are geared toward espresso brewing and are intended as a tool to help you get perfect extraction. Now, here’s a summary of brewing modes:

  • The first mode: Weighing-only mode is a simple starting point. This is the automatic mode when you first use the scale. It only shows a single display of the weight in grams or ounces.
  • The second mode: Dual display mode is useful for espresso shots. It shows the weight on the right and a timer on the left. You can simply press the on and off buttons on the left to start or stop the timer. You can tare the espresso cup by pressing the T and then pressing the power button to start the timer as soon as the espresso machine starts.
  • The third mode: The flow mode is useful for espresso brewing, and it automatically starts a timer after detecting the first drops of water. The scale displays a water droplet icon on the right side of the display. The timer stops after the espresso stops pouring. You can even reset the time at each pour to improve the management of time periods.
  • The fourth mode: Auto-Tare works like the mode above, but it has an auto-tare step. Water flows, and the timer starts. Water flow ceases, and the timer stops. It’s useful when you want to tare the scale automatically.
  • The fifth mode: Another Auto-Tare that is similar to the previous one, but it’s best used for measuring the full extraction time, including pre-infusion. You place a cup on a scale, and it’s auto-tared. The scale starts the timer immediately and weighs the shot. Once the shot is done, the timer stops automatically.
  • The sixth mode: This mode will tear off new weight, which is useful for different sizes of espresso cups. It auto-tares the weight on the scale and automatically starts the shot timer. It’s best used when you want to measure the shot’s weight and not check the pour time.

Bluetooth Connectivity

The final special feature is smart connectivity. All Acaia scales are smart scales, which means they have Bluetooth 4.0 capability, and you can use them via apps (yes, more than one app).

Here’s a breakdown of all apps the Acaia Lunar is compatible with:

  • Brewmaster: Useful for storing data, such as flow rate, weight, extraction, and more. The app gives you a visual graph of the extraction.
  • Brewbar: Best used in commercial settings. You can sync several scales.
  • Acaia coffee: It lets you connect with other coffee enthusiasts, review espresso beans, and keep track of the coffee you tried.
  • Acaia updater: Updates the Acaia scale with the latest software.
  • Smart espresso profiler: You need a Smart Espresso Profiler tool to measure the group head pressure and the Lunar scale to get the brew weight info. The app shows real-time pressure and flow rate during brewing.

The apps are free, and you can download them separately. And herein lies our main gripe with the Acaia apps — who wants SIX separate coffee scale apps on their phone? It would be much better if the company integrated all six apps into one.


  • Low profile and compact design
  • Great for espresso shots
  • Extremely precise
  • Attractive design
  • Durable build


  • Not best for manual brewing modes
  • Sensitive to weight changes
  • Too many apps
  • Expensive

Do Not Buy Acaia Lunar Scale If…

  • You’re on a budget — Acaia Lunar has some impressive tech and build, but it’s one of the most expensive scales. If you’re looking for something more affordable, check out the Timemore Black Mirror. It costs about a fifth of the Acaia Lunar and is suitable for different brewing styles. It also has a stylish design and is one of the best value-to-price coffee scales on the market.
  • You want a larger scale — We briefly did an Acaia Pearl vs Lunar size comparison above, but here’s the gist: Acaia Lunar is a small scale, which makes it ideal for espresso. But, if you want a scale you can use for espresso but also manual brewing, the Acaia Pearl model is a better choice. It’s small enough to take with you on a trip but large enough to fit larger coffee makers.
  • You want a scale for drip coffee — The Hario V60 drip scale may not be as aesthetically pleasing as the Acaia ones. But this Hario scale has plenty of features that help you get a consistent brew. It has a timer automatic shut-off feature that saves the batteries and provides readings to the 0.1 g.

The Verdict

The Acaia Lunar scale has a stunning design, many impressive modes, Bluetooth connectivity, and is extremely precise. This scale is best suited for espresso brewing, and it’s made to fit onto the espresso drip tray and has several modes that help you improve your shot.

Overall, the Lunar is a top-notch quality scale and a hit in the specialty coffee community. If you mostly brew espresso, you’ll LOVE it.

Acaia Lunar Original

Click to check price

  1. Do You Need a Scale to Make Coffee? (n.d.). Blue Bottle Coffee Lab. Retrieved April 19, 2023, from https://blog.bluebottlecoffee.com/posts/do-you-need-a-scale-to-make-coffee
  2. Weighty Decisions: Coffee Scales in Depth | Five Senses Coffee. (n.d.). Fivesenses.com.au. Retrieved April 19, 2023, from https://fivesenses.com.au/blogs/news/weighty-decisions-coffee-scales-depth/
  3. Industries, L. (2019, March 21). What is Anodized Aluminum? – Lorin Industries A World Leader in Aluminum Anodizing. Lorin Industries – Aluminum Coil Anodizing and Finishing. https://www.lorin.com/what-is-anodized-aluminum/
Marina Maletic
I grew up surrounded by people who drink Turkish coffee. This was the only kind of coffee I knew for a long time, and wasn’t a fan of because it was too strong. It wasn’t until I started uni that I delved more into the world of coffee by trying out my classmate’s Aero Press. Nowadays, I can’t imagine starting a day without my espresso machine. If I’m not drinking or writing about coffee, I’m connecting with fellow coffee enthusiasts and looking up ways to perfect my dialing in technique.

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