Sasa Sestic OCD

Ona Coffee Director and 2015 World Barista Champion (WBC) Sasa Sestic sometimes describes himself as “a little OCD” about coffee quality. So much so that he has created a tool to aid his compulsion for perfection.

Aptly titled the Ona Coffee Distributor (OCD), the round device is simply placed inside a dosed basket of coffee, and with just a few spins of the device, hey presto, even distribution of coffee at every section of the basket.

“Making delicious coffee is all about understanding variables and taking control of them. Distribution creates major variables for the quality and consistency of how coffee tastes,” Sasa says. “The OCD eliminates those inconsistencies.”

When a 58-millimetre basket is put into an espresso machine to start an extraction with nine bars of pressure, Sasa says the face of the basket will give the same resistance in all parts of the cake. “The result is very consistent coffee,” he says.

The OCD has four angled slopes that evenly glides the coffee around in a circle to create a puck of even density. It’s not pushing the grounds inside but instead spreading the coffee granules evenly across the basket face. This creates a perfectly flat surface to tamp upon, creating more consistent puck density. It can be adjusted to suit a range of doses, depending on specific roasting styles.

“No more dirty, cracked coffee barista fingers after a day of service on the espresso machine,” Sasa says.

Sasa first conceived the OCD in 2012 but it’s only since January 2016 that it’s finally been ready to share with the world. After extensive taste testing with multiple coffees and different roasting styles, Sasa found that any form of collapsing to stratify grinds creates very inconsistent extraction and qualities of taste (separate to yield).

“Each barista will collapse the dose differently, creating yet another inconsistency in the café,” Sasa says. “The OCD takes the same time to create a more evenly distributed puck, giving more consistent and delicious extractions.”

He adds that improper or rushed distribution is likely to channel, which is disastrous to taste. Micro-channeling is difficult to visually identify. But this variable is removed with the OCD.

To test its efficiency, Ona Coffee Head Trainer Hugh Kelly put the OCD to the test. He tested the device under different conditions, such as changing different coffee, recipes, and different locations and grinders (using an Anfim S450 and Mahlkönig K30 Air).

In Hugh’s testing, the OCD was set to a depth of nine millimetres with Ims and Vst 20-gram baskets. To assess extraction consistency, different distribution techniques were compared, included collapsing, careful circular distribution with the hand, back-forth-back distribution with a finger, and with the OCD set to the correct height.

The range and standard deviation were recorded for each data set and provide a general indicator of consistency. In the first test using a Vst 20-gram basket, Anfirm grinder and La Marzocco machine, the OCD recorded an average range of 0.5 and a deviation of 0.0014. In the second test Hugh used an Ims 20-gram basket, Anfim S450 and San Remo Opera machine. This time the OCD had an average range of 0.4 and a deviation of 0.0016.

In both tests the OCD and circular hand distribution were found to have the smallest ranges and similar deviations. The measurements indicated an improved consistency over other methods.

The next test of the OCD involved a blind taste test with three participants using a WBC-style of scoring for taste and tactile balance to come up with an overall rank out of the four coffees presented. In each test, four cups were presented, marked underneath, and extracted to the same recipe. Participants ranked the cups 4 (best) to 1(worst) and results were revealed after scoring was completed to minimise influence. In the first two tests the OCD scored 3.6, in the third test it scored 3.8, and in the fourth and fifth tests it scored 3.4, overall out-scoring every other method of distribution.

Hugh says this general high scoring trend in taste testing found that OCD-distributed shots usually had rounder acidity, lower astringency, cleaner finish, and a smoother transition of elements over the palate.
“The testing provides two indications supporting our belief that the OCD distribution tool is of benefit to consistency and quality of espresso,” Hugh says.

Sasa adds that the OCD was the top ranked method in every test above bar one, where very careful hand distribution was the winner. “The OCD is one step closer to giving us the consistency and most tasty espressos we could have,” he says. “It distributes every single basket, every single time, exactly the same.”

Don’t just take Sasa’s word for it, test the OCD for yourself.

For all enquiries contact, or call 02 6162 3321.

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