Osma Recirculating Brewer

Osma is a genuinely new way to make coffee: instead of passing water through the grounds once, it recirculates it, pumping water down through the coffee and back into the same container, again and again, until the drink is as strong as you want. Because it doesn’t rely on heat, it works with any water temperature, including ice-cold. The countertop Osma Pro adds acoustic vibration to create microcavitation in the coffee bed, and makes a strong, cold, espresso-like drink in about two minutes. Here’s how it works.

The short version

• Water recirculates through the coffee until it reaches the strength you want.
• Any temperature, from ice-cold to hot; Osma doesn’t heat the water.
• About two minutes for a strong cold coffee.
• Osma Pro uses acoustic waves to create microcavitation.
• From California, designed by Joey Roth with Chromatic Coffee.

How does Osma work?

Recirculation. “Almost all forms of coffee-making are unidirectional,” TechCrunch explains: water meets the coffee once and comes out. Osma “sucks up the water, passes it through the grounds and agitates it, then puts it back in the same vessel, where it is sucked up and passed through again.” Stop the cycle early for a lighter brew, or later for a heavier one; co-founder Joey Roth finds a sweet spot at about two minutes.

Gentle pressure. In the original Osma, Daily Coffee News reports, the pump, the filter and the coffee together build “a slight build-up of pressure”, and “as the coffee blooms, the pod becomes more constrictive of the water flow, and pressure in the pod climbs gently,” Roth said. That, plus the constant cycling, “greatly speeds up the extraction”.

Microcavitation (Osma Pro). Espresso extracts flavour partly through microcavitation, tiny bubbles that form and collapse under heat and pressure. Cold water can’t do that on its own. Roth and co-founder Dan Yue found that cavitation was “the magic switch”, and spent about two years developing a way to create it acoustically, in a tightly packed basket of ground coffee, TechCrunch reports.

Which Osma?

	Original Osma	Osma Pro
Launched	December 2020	2021
Type	Portable, battery-powered	Countertop, stainless steel
How it brews	Pump recirculates water through a pod	Recirculation plus acoustic agitation
Brew time	About 1 to 2 minutes	About 2 minutes (TechCrunch); about 90 seconds (WERD)
Output	Hot or cold	8 to 12 oz
Pods	Compostable sugarcane-fibre pods, empty or filled by Chromatic Coffee	Basket
Price	$185 with 12 pods	$695

The original Osma’s battery lasted about 20 brews per charge, and its app let you design recipes with continuous or intermittent flow, Daily Coffee News says. TechCrunch describes the portable version as a development dead end once the countertop version improved; WERD says the Osma Pro was hand-built in Oregon in a limited run of 1,000 machines.

Why does it matter?

For cafés, TechCrunch argues, strong cold coffee on demand could replace making cold brew a day ahead, risking running out, or pouring hot coffee over ice. Nobody has settled on a name for the drink yet: TechCrunch suggested “coldpresso”; Roth suggested “cold flash”.

General guidance only. Follow the maker’s instructions, and keep electrical parts away from water when cleaning.

Osma vs other methods

• Cold brew: the slow, overnight way to make cold coffee.
• Ultrasonic cold brew: another fast cold method using sound waves.
• Snap-chilled coffee: hot-brewed coffee chilled instantly.
• Kyoto slow drip: the drink Roth compared Osma’s coffee to.

Explore every cold method in the cold chapter.