For more than a decade now, everyone from the world's top coffee professionals to the most isolated home coffee enthusiast has been bemoaning a very glaring omission from the world of coffee and espresso grinders: the ability to accurately grind a specific amount of coffee by weight and to do it repeatedly.



Grinder manufacturers have for years now either declared the weighty problem to be too difficult, or have just chosen to ignore it. It has even happened in CoffeeGeek's forums: representatives of major grinder manufacturers have discussed the difficulties of incorporating accurate scales into their grinders, and having the grinder tied to these scales so that if you typed in 19.2 grams, you got 19.2 grams in the filter basket.



Baratza, a company based out of Bellevue Washington knows only too well about these difficulties. But they also know about the desire, heck, the demand by coffee and espresso professionals to have a grinder capable of accurate weight based dosing for a wide variety of coffee needs, from the smallest cupping volumes (12 grams) on up to 1 litre or more brewing volumes (64-80 grams of coffee).



In the past few years, the company set about to tackle this problem. And at SCAA in Houston in just a few short weeks, they will be demonstrating some late-prototype devices that bring the dream of accurate, weight-based dosing grinders to reality.



These two products are the Esatto Grinder Attachment accessory, and a new Baratza Vario model, called the Vario-E. The Esatto Grinder Attachment This was the initial product dreamed up by Kyle Anderson at Baratza to answer the needs of baristas and coffee professionals. He had heard for a long time about the desire to have a weight-based dosing solution for grinders.



"As we watched the slow coffee movement -- the single cup brewing method -- grow, we heard more and more from people the importance of weighing the coffee." Anderson said. "At the request of a coffee shop owner who uses our Virtuoso for single cup brewing, well, he asked about the possibility of a grinder that weighed the coffee automatically. I drew him a sketch -- literally on a napkin -- of an example of such a solution and he shouted 'yes, that's it!' That was literally how the Esatto was born. The Vario-E was just a logical extension of the same idea."



The Esatto, as you can see in the picture to the right, is a 12 1/4" by 5 1/4" wide attachment that adds about 1" overall height to the grinder it is attached to. It is compatible with all existing Maestro Plus, Virtuoso and Preciso grinders.



The way it works is fairly straightforward. Your grinder actually slots into this device. You take the grinder's existing cord and tuck it into the grinder as much as you can. The remaining powercord fits into a recess in the back of the Esatto attachment. The grinder's powercord plugs into the Esatto itself. One screw tightens up everything, and after this point, you have a weight-based dosing grinder, with guaranteed accuracy better than 0.5g, and in reality, accuracy down to 0.2g or tighter (all numbers subject to final testing, which is happening in May). For all brewing methods save for espresso, 0.5 grams accurate is not only good, but I'd go so far as to call it near perfect: I would challenge anyone to tell any difference in a cup of coffee brewed with 28g vs 28.5g. It cannot be done.



For espresso, you want more accuracy, and 0.2g is not only within acceptable range, I'd say it is definitely within a target range that even the world's top espresso judges would be hard pressed to taste a difference in. In coffee cuppings, where the average measurement is 12-14 grams, accuracy is also extremely important but again, a 0.2 gram variance is within most cupper's tolerable limits. (I talk more about accuracy below in this article). Esatto Controls

The Esatto controls will be very familiar to Vario owners - three preset buttons, up and down buttons, and a multi function button that starts or stops grinding, with an option to TARE (zero) the amount if pressed and held.

Grinder Dial Lock

When converted, the host grinder is always "on" (the timer dial is in an operational position), but the Esatto attachment controls when the grinder is actually running or not.

The Esatto will be demonstrated in a late-model, working prototype at this year's SCAA show in Houston on April 28 to May 1, 2011. Baratza's booth is #1825.



Even better, Baratza expects to start shipping the Esatto in June, 2011. The projected price? $149 US dollars. The Vario-E Weight Based Dosing Grinder Because of the digital vs. mechanical natures of the Vario grinder versus the Preciso / Virtuoso / Maestro Plus, creating an Esatto attachment that would also work with the Vario was impossible. The problem is the boot-up time the Vario required each time it is powered on.



Anderson's solution for this? Just design a brand new grinder with the Esatto components built in. After all, the Vario had internal architecture, cpu power and memory to handle all that the Esatto does. So that's exactly what he did - they took the company's Vario model, took out the timing functionality, and built into it the weight-based dosing system. The scale system is incorporated into the same footprint as the existing Vario. Everything's built in, and with the grounds-bin in place, you'd be hard pressed to tell a Vario-E from a Vario model. Vario-E Prototype

This is the Vario-E, in prototype format. It still has the same control layout (and markings, for now) as the Vario model has. Note the bin size difference, including gaps and the handle up top.

Vario-E Scale Sensor

Here's the major difference - the Vario-E has the built in scale sensor pad on the bottom. Right now the bin works with it; in future, Baratza may be able to do a "cupping cup" shelf to slot over this for grinding directly into a receptacle.

Vario-E Scale Sensor

The scale and weighing system is tightly integrated into the Vario's body.

Bin closeup

The bin is designed around the scale. Note the gaps and handle; the bin is designed to float on the scale sensor and not touch the grinder's body.

Sensor Closeup

In future, there are other potential applications for this grinder, including a possible cupping receptacle shelf for grinding directly into a vessel.

There are a few things you're giving up with the Vario-E grinder, and they are important to note. First, there is no portaholder included with the Vario-E grinder because the weight-based dosing system is incompatible with portafilters (again, more on this below). Second, the timer elements of the grinder are stripped out of the onboard programming. Most of the controls are exactly the same, but on the Vario-E they correspond and are related to weight based settings.



Also, existing Vario machines are in no way compatible (upgradable) to the Vario-E model. With this new machine, Baratza has a one-two punch in their Vario lineup: a digital timer version, or a digital weight dosing version.



Probably the best news is the price. Where the Esatto attachment is $149, the Vario-E is only $100 more than a standard Vario - the projected MSRP price will be $549. And this product should also be ready to ship sometime in June, 2011. Again, Baratza will have a working prototype at the SCAA show in Houston on April 28 to May 1, 2011. Baratza's booth is #1825. What Weight-Based Dosing Means In short, weight-based dosing on a grinder means better coffee for you and me.



It means we have highly repeatable results from a grinder that ensure consistency from cup to cup. That's the key with both the Esatto and the Vario-E: even though the grind may be off by 0.1 or 0.2g from what you programmed in, it will always be off by the same amount as long as you don't change the whole bean coffee or grind fineness setting.



What this means is this: if you want to grind 20 batches for press pots, the Esatto system delivers you exactly the same dose for all 20 pots. There is little or no measurable variance in weight from the first batch to the last. The only variance is what you programmed in vs what the grinder grinds into the bin, and that variance is around 0.2g or better.



This is especially a boon to commercial cafes doing by the cup slow coffee brewing. Imagine a cafe with a four-station Hario V60 brewing setup. They have four Vario-E grinders, each with its own coffee. After a dial in process, they find that their Honduran coffee is best at 22g dose, but their Ethiopian is best at 19.5g (as dosed by the Vario-Es). Each Vario can be set up for its specific coffee and all day long, it will grind out exacting doses of 22 grams. Or 19.5 grams. or whatever the barista programmed in.



This means no secondary step of weighing the coffee - just set, and forget. Given how (relatively) fast the Vario (and Preciso) grind at (2.2/2.5g per second for drip) this can be a real time saver in most cafes.



It also means it is a real coffee saver too. Since the grinder only grinds out your exact dose, it means little or no waste: the cafe gets more cups per lb brewed than with any other grinder. Over the course of a day, week, month, this can add up to tens and hundreds of dollars saved. One of my local cafe friends believes the Vario-E can pay for itself within 2 months or less in his cafe with its near-zero coffee waste.



In the home, weight based dosing is also highly desired for many reasons. I'm just going to present one out of the box example:



You're the home barista. You geek out on coffee, you measure everything. You weigh everything. You time everything. Meanwhile, your spouse just wants a good cup of coffee. This is one more step to he or she being able to have that, on their own, thanks to the grinder doing the weighing for them. You program in the weights and set the preset buttons (there's three). In the morning, your spouse just has to hit one button and voila, the grinder has ground out an exact dose for their morning press pot. Or morning espresso. No muss, no fuss, no scales, no obsessive compulsive home coffee geek looking over their shoulders. Developing the Esatto Weight Based Doser Attachment Having an idea on a napkin doesn't translate very well at times to an actual product. There were many unforeseen challenges for Anderson in developing the Esatto Attachment. "Accuracy, repeatability, ease of use, compatibility with current grinders, ease of assembly for customers, and a few others I'm sure that will come to mind later," he said, when asked about these challenges.



Accuracy was probably the biggest challenge. From the get go, Anderson not only wanted this solution for manual pourover and press pot users, but for the most demanding of coffee brewing methods: espresso. And it was this quest for accuracy in the settings versus output that put the idea of having a portafilter system on the shelf: the Esatto (and the Vario-E) both only work with a coffee grinds bin (I have more on the portafilter issues below).



By having the Esatto grind into a grinds bin, accuracy is pretty tight on this new grinder system. "we can deliver close to 0.1 grams accuracy with the grinder," said Anderson. "There is variation depending on which grinder is used -- the Maestro Plus / Virtuoso versus the Preciso -- and the degree of grind fineness selected by the user." I explain more about this below in the Challenges section. The Challenges Weight-based dosing on a grinder is more challenging than you might think it is on the surface. There are many factors in play that can disrupt the accuracy of such a system, especially when you want accuracy down to 0.1 grams. It is these very challenges that have caused many commercial grinder manufacturers to not even bother developing a weight-based dosing system for their grinders. Here are just a few of them.



Portafilters: The Esatto and Vario-E grinders are not portafilter compatible. And this is not for lack of trying.



The problem has to do with the handle on the portafilter. This creates a weight unbalance, one that is physically corrected by Baratza's hook and fork design of their Portaholder (on traditional espresso grinders, this is corrected by you, the barista, holding the handle while dosing). Even though the Portaholder corrects this with a hook, the weight is still off balance and because of this, is nearly impossible to accurately weigh and tare using a conventional lever arm scale system (which weighs from below).



It is impossible because of the different sizes, shapes and weights of various portafilters. If every portafilter in every machine was exactly the same shape, dimensions, weight and design, then Baratza could have programmed in a calibration offset to allow for the use of their Portaholder and a portafilter. However, since reality is there are literally thousands of variants of portafilter designs (and even more when you factor in filter baskets used), this could not be overcome by any fancy programming - the physics of how a scale works and how the portafilter's handle is offset to the weight prevented this.



Because of this, the Esatto attachment and the Vario-E grinders cannot do weight-based dosing directly into a portafilter. But, since the grinder is guaranteed to be accurate down to 0.5g, and is generally accurate down to 0.2g or better, grinding into the catcher bin then pouring the ground coffee into a portafilter filter is a good solution for very accurate, on the fly grinding by weight for espresso preparation.



One other positive note for espresso people: the finer the grind, the more accurate the setting vs. real weight of coffee is on the Esatto system. This is because a finer grind takes a bit longer to do per gram than a drip or press grind.



The Float: If you manage to set up a grinder with an incorporated 0.1g resolution scale, and have digital controls set so as soon as the scale reads your pre-programmed amount (let's say 30 grams for sake of argument) the grinder stops, several elements come into play: if you stop the grinder as soon as the scale hits 30g, there's still some residual grounds that will fall into the grinds-catcher, bringing your total up. On a grinder like the Anfim Super Caimano, this could be another 1 to 2.5 grams. On the Vario, with its near 0g retention, it still can be as much as 0.5g.



Other problems are present: for example, even if the digital controls stop the grinder as soon as it measures 30 grams in weighted output, the burrs don't instantly stop - they spin down. The spin down is quick - less than half a second, but spin down none the less, chewing up more grounds to fall out. This can be another small amount of coffee, depending on the grind setting chosen.



A third problem is the fineness of the grinds. A grinder doing an espresso grind takes longer to do a gram of ground coffee than a grinder set for press pot. This length of grinding time factors into any kind of solution for the spin down and residual fall of grinds.



A fourth problem is how fast the grinder is: for example, the Esatto attachment fits the Maestro Plus, the Virtuoso and the Preciso, but the Preciso grinds twice as fast as the Virtuoso does. And a firth problem is the scale itself (covered more below) and how much lag time it has in reading weights and sending that information to the Esatto's microprocessor.



With all of these issues, you have to start looking into using algorithms (if the grinder's CPU knows in realtime what the grinder output per second is, and the grind fineness level is) or preset "offsets" (ie, if you program in doing 30 grams, the grinder will actually stop the motor at around 29 grams) in order to have as accurate a possible dose.



And the latter is what Baratza has done with their Esatto attachment - they've programmed in a preset offset number that finds a happy medium between the three grinders it is built for, and what happens between the range of turkish grind and press pot grind. It does reduce the accuracy a bit of the device - current testing shows it to be within 0.2g on average, and sometimes as much as 0.1g. Even a cupping sample can live with a 0.2g variance, so the target they've achieved is pretty remarkable.



On the Vario-E, things should be even better, since Baratza's CPU knows what grinder it is being used with, and the calibration offset would have a tighter tolerance.



The Scale Itself: you may have noticed that most scales with a 0.1g resolution say just that: "0.1g resolution". They do not say "0.1g accurate". In fact, most scales under $500 are only truly accurate to within 0.3-0.5g, even the scales that resolve to 0.01g. It has to do with simple physics, dust, ambient temperatures, airflow and more. Even light shining on a scale (especially sunlight) can affect accuracy by as much as 0.2g or greater.



Baratza tested many scale components, and eventually settled upon a 300g max weight, 0.1g resolution scale that had a very quick reading time and was reasonably accurate. Could it be better? It could be, but this would mean adding $100s to the price of the product.



System Compatibility. The desire from the get go to make the Esatto attachment "universally compatible" with Baratza's entire lineup was quickly beaten down by the low end and high end of their existing grinder lineup. On the low end, the Maestro had a different physical bottom and different mechanical switch, making it difficult to design a universal mounting base that would work with it and the rest of the Baratza lineup. On the high end, the Vario had challenges with it's boot up time lag and different base.



So Baratza decided to built the Esatto to fit three of its five grinders: the Preciso, the Virtuoso, and the Maestro Plus. Even so, there are enough differences between the three grinders that making the Esatto compatible with all three out of the box presented some unique design challenges. Availability Baratza is demonstrating the Esatto Grinder Attachment and the Vario-E grinder at this year's SCAA show in Houston, between April 28 and May 1. They are also taking orders at that time. Both products should be available in late June in many retail channels around North America, and should show up in Europe, Asia and Australia / New Zealand later this year.



The Esatto attachment has a projected MSRP price of $149. The Vario-E grinder is projected for a MSRP of $549. We will be getting early production models of both products and will put them through a series of tests for a future article on CoffeeGeek.



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