From the Grounds Up

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Conical&FlatBurrs_1st-LineEquipment

When David Schloss was pondering which grinders to buy for his two-location Gypsy Donut and Espresso Bar in New York State, he knew it was a major decision. “We’re really particular about the way we make espresso,” he says. “We’re the only shop I know in the area that weighs every shot we pull.” The shops are also busy, and Schloss knew he wanted something that could stand up to constant use resulting from long lines of customers. “A more powerful machine is going to give you durability,” he says, “plus that consistency from shot to shot.”

Schloss finally decided on Mazzer electronic espresso grinders, with different models for the different needs of the two locations. At his primary shop in Nyack, he installed a Mazzer Robur E for the main espresso grinder and a Super Jolly E for decaf or single-origin. At the second, smaller location—a café inside a bicycle store in Piermont—he installed a Major E for espresso. Because very few decaf orders are placed at that location, Gypsy Donut turned to a smaller retail grinder for decaf.

Burrs_NuovaSimonelliWith grinding fresh for each order now a common practice among top-quality cafés, having reliable, high-performing commercial grinders in your arsenal is a necessity. But when you’re spending the big dollars to achieve that, how do you decide exactly which direction to go? Conical burrs or flat burrs? Dosers or doserless? What about keeping the grinder cool? And with the rising popularity of single-cup brewing, what type of grinders produce the best results in that realm? We checked in with the experts for the latest in heating technology, dosing performance and much more.

First things first, the basics: The vast majority of modern espresso grinders are burr grinders, meaning they use two hard surfaces to do the grinding, and conical burrs and flat burrs are the two most common types. One of a grinder’s goals is to produce uniform particle size with very little “fines,” which are particles of coffee that are smaller than the rest of the grind. At grinder manufacturer Nuova Simonelli, president Roberto Bresciani says all of the company’s grinders use flat burrs, largely because of the “fines” issue. “We find that the conical grind profile produces more fines, so the fines migrate and choke off the extraction and you don’t get a smooth flow,” says Bresciani. “With the flat burrs on our grinders, we find that we get a very uniform pour rate.”

At New Jersey-based 1st-line Equipment, which sells grinders from several manufacturers, business partner Jim Piccinich says he’ll recommend both flat and conical burr grinders, and that the size of the burr can be more important than the type. “I do have a preference toward larger burrs because they will allow you to grind more coffee continuously and have less heat buildup on the burrs,” he says.

One of the decisions the user must make when choosing a grinder pertains to dosing—espresso grinders come in doser models and doserless models. In the former, ground coffee goes into a chamber from which it is dispersed, while doserless grinders empty directly into a machine’s portafilter. Dosers are common in high-volume environments because they work quickly—coffee is ground into allotted slots that rotate as a lever is pulled to provide the proper dose of grounds into the portafilter. However, one criticism of the doser method is that coffee can get stale as it’s sitting in the doser waiting to be dumped into the portafilter. “Coffee’s optimal flavor profile is within seven minutes of when it’s ground,” says Piccinich, “then the grinds start degassing, and you also start losing some of the aroma.”

Grinder with doser.
Grinder with doser.

Doser grinders are still common at high-quality shops, but they were virtually the norm until recent years, when enterprising shop owners and baristas began creating their own doserless

Doserless grinder.
Doserless grinder.

models by removing the dosers and emptying the grinder directly into the portafilter. However, that practice didn’t always result in the fresh coffee users expected. “What everybody figured out with a lot of those modified doser grinders was that there was still a large channel of pre-ground coffee in them,” says Bresciani of Nuova Simonelli. “So even though it was clumping out each time they pressed the button, a lot of that coffee had been pre-ground and was being stored in a chamber.” Many manufacturers, including Nuova Simonelli, now make doserless grinders that aim to do away with that channel of stale coffee and grind fresh beans into the portafilter each time.

Another important issue with grinders is their temperature: As Schloss at Gypsy Donut and Espresso Bar has witnessed, during high-volume times when consecutive shots are being pulled, the grinder will heat up. “What you’re effectively doing then is starting to cook the coffee inside the grinder, and that’s something you don’t want,” says Schloss. “It might not affect the shot you’re pouring, but if the coffee sits on the burrs for a while, the next shot might not taste as good.” He adds that he chose the powerful Mazzer models because they have temperature-control fans inside that kick on when the machine starts to heat up, preserving the taste of the coffee and ensuring consistent results from shot to shot.

But the temperature concerns with grinders is not relegated to overheating. Bresciani at Nuova Simonelli says a grinder will also perform differently when it’s first turned on. “We discovered that how quickly burrs will cut coffee changes if the burrs are cold versus hot,” he says. “It presents a problem for consistency because, for example, you may program a doserless grinder to activate for five seconds. But five seconds on a cold grinder and five seconds on a hot grinder will give you two different doses.”

Aiming to address this issue, Nuova Simonelli developed Clima-Pro, a patent-pending thermal-stabilization system for grinders that Bresciani says “preheats the grinder so that in the morning you’re starting off at an optimal operating temperature. And then also the temperature-stability system is thermostatically controlled so that if you start to really use the grinder in a high-volume situation, it will cool it.” The new technology is available in Nuova Simonelli’s Mythos One Clima-Pro Grinder that debuted last year.

Espresso is not the only application for which a grinder will be used: With more and more shops having single-cup brewing on the menu, café owners must also decide how to grind beans for those offerings—the key difference, of course, being that it requires a much coarser grind than for espresso.

Some shops opt for compact models designed for small-batch coffee grinding: One example is the 804 series from Ditting USA, which was originally designed for grinding only into coffee bags or filters, but its KR804 model was modified for single-cup brewing. “The modification allows the barista the benefit of the discharge tube with the knocker to easily clean out the tube between grindings,” says Ditting USA president Nancy Wideman, “and it provides a stronger support when grinding into a French press, cup or other vessel.”

At Gypsy Donut, Schloss opts for a bulk coffee grinder with different settings marked off to grind for each specific brew method. “If somebody’s grinding coffee for a V-60, they just turn it to the pour-over setting. If somebody’s doing something for French press, they just switch it over,” he says. “And then we just check that regularly and taste the coffee to make sure that it’s consistently tasting how it’s supposed to taste.”

And then some shops will employ doserless espresso grinders—dialed to coarser settings—for single-cup brewing. For example, roaster-retailer Blue Bottle Coffee uses Nuova Simonelli’s Mythos grinder for the brew bars at its cafés.

As with any decision you make related to your shop, it comes down to assessing which grinder will best fit your requirements. “The most important thing for the café owner is determining what the needs are and then matching those needs,” says Piccinich of 1st-line. Whether you seek a grinder with or without a doser, one capable of grinding coarse coffee for single-cup brewing, or a machine that accomplishes an entirely different task, there are plenty of options available in the vast world of specialty coffee to fit your needs.

—Chris Ryan is the editor of Fresh Cup.