How do I get started on the Osma?

Grind coffee to espresso fineness (200-300 micron).Fill the portafilter with a heaping mound of the ground coffee (25+ grams). Use the distributor to first tamp the heap of coffee down. Then spin the distributor a few times to evenly settle the grounds in the portafilter. 

Insert the portafilter into the Osma. Fill a cup with room temperature water and place it to the side of the Osma with the single pass straw inserted. Place an empty cup with ice on the drip tray under the portafilter. 

Pre infuse your coffee grounds: Press the power button on for half a second then press again to stop (or use the button as a momentary switch by only partially pressing it in). Wait two seconds for the coffee to bloom. Repeat the on/off cycle until you see the first drops of coffee come out of the portafilter. Wait 30 more seconds then press the power button and run until the desired amount of coffee has been extracted. We recommend an ideal extraction output of 5 oz (150 ml) but adjust to your taste.

What is pre-infusion?

Pre-infusion is the process of allowing water to saturate in the coffee grounds and let the coffee bloom before pulling your extraction. On the Osma, you pre-infuse by pumping the power button on/off. We recommend starting with .5 seconds on/2 seconds off until you see coffee dripping from the portafilter, then wait 30 seconds then run the Osma. However you can try any combination of pre-infusion: try a longer on cycle or an off cycle of 60+ seconds. Our partners at Chromatic have optimized their Osma, with a gicleur low flow shower screen screw, for two cycles of pre-infusion at 3 seconds on/10 seconds off.

What grind should I use?

200 - 300 micron is ideal. This is on the finer end of "espresso" grind. Here is an example of what that grind size looks like, with a quarter for scale: 

What roast should I use with the Osma?

Use the coffee you like. If you want to emulate traditional cold brew use a darker roast, but the Osma works with any high quality coffee.

Do you have specific recipes you recommend?

Visit our testimonials page in the menu!

What is the optimal extraction yield for the Osma? 

Osma's remarkable efficiency allows you to make everything from an intense (18.0+ TDS) 3oz cold espresso shot to a tall 7oz similar in strength to traditional immersion cold brew (2.0 TDS)

When should I use recirculation vs single pass?

We generally recommend single pass for cold espresso, and either single pass or recirculation for cold brew. Try experimenting with both to see which you prefer. Recirculation also can work for tea--we recommend putting a filter over the loose leaves in the portafilter to minimize migration of tea debris.

Can the Osma be customized?

You can customize your current Osma as desired: e61/ Marzocco standard 58mm portafilters, baskets, gaskets, shower screens and shower screen screws are all fully compatible. 

Specific recommendations from our Discord:

  • Vidastech Retina Diffuser Screw for La Marzocco IMS Shower Screen
  • Precision shower screen MARZOCCO - IMS MA200IM - OD56.4 mm 98x3 mm holes 200 
  • Normcore 58.5mm Puck Screen/Espresso Portafilter Lower Shower Screen/Contact Screen - 306 Stainless Steel
  • Pesado Stainless Steel Portafilter Head and Spout - to fit LM/E61
  • Filter-holder Handle M12 Black - ASTORIA - ORCHESTRALE - WEGA

Demo from Hiver at Chromatic Coffee on installing a gicleur to the Osma

Can Osma make hot coffee as well?

We recommend using 4-5 oz of room temperature water with at least 21 grams of coffee in the portafilter to make a concentrate. Then use 6-8 oz of drinking temperature water (70 c) as a bypass (dilution) by pouring it on top of the concentrate. This will yield a remarkably complex cup of drip-strength coffee at perfect drinking temperature.  

Can Osma heat up or cool down water on its own?

Osma brews using the temperature of the water that you pour into its cup. It can't make water hot or cold on its own. An active chiller modular upgrade is still on our roadmap. It will probably be based on a peltier array, and existing customers will have first access once it’s available.

How do I clean my Osma?

Make sure the portafilter is empty, then take a large cup or jar of fresh water, insert the intake straw, place it under the portafilter, and turn on your Osma. The water will change from clear to brownish as coffee residue is whisked away from all internal surfaces and into the cup.

How does Osma speed up the typically slow cold brew process?

Our patent-pending process uses recirculation and microcavitation to extract the compounds that comprise coffee's taste and aroma. This lets you make cold extraction coffee in minutes rather than hours.

How does the taste compare side-by-side with traditional cold brew and with iced coffee?

Osma is not designed to exactly replicate immersion cold brew. This is a fundamentally new way to brew coffee. It’s a combination of an espresso with fresh crisp citrus volatility and texture, and cold brew balance and smoothness and representation of a different spectrum of flavors and aromas. With the Osma, you preserve all the compounds of fresh coffee, unlike cold brew which loses time sensitive compounds because of its 12 hour+ process. You also get back the heat sensitive compounds lost in a hot process–retaining the smoother, delicate flavors in cold coffee. Osma captures the widest range of flavor and aroma compounds by being both a fast and cold extraction method. And its unique creamy texture is derived from the microbubbles our process produces in the coffee, which literally make the flavor transfer more chemically efficient. Hot espresso over ice or traditional 12+ hour cold brew will not have the same spectrum of compounds as the Osma. Because of this different process, coffee roasts that you are used to from other extraction methods will taste different on the Osma–we encourage you to experiment.

How can I dial in the taste?

The Osma makes a single serving of cold extraction coffee. We recommend optimizing for a 4-6oz output for a single serving, which should deliver a nicely concentrated cold extraction coffee. To dial in the strength and taste of your extraction, try different pre-infusion cycles, more coffee grounds, a low flow shower screen screw, a coarser grind size with tighter tamping, or experiment with different coffee roasts.

Does Osma work with tea?

Yes, we've had success brewing a variety of teas. We're in the process of developing tea recipes and encourage you to experiment with your favorite varieties.

More questions? Contact us at support@drinkosma.com