# Osma Recirculating Brewer Source: https://dailyextraction.com/methods/osma/ Last updated: 2026-10-20 > Osma pumps water down through a basket of ground coffee and back into the same container, over and over, until the coffee reaches the strength you want. In the countertop Osma Pro, acoustic vibration creates tiny collapsing bubbles (microcavitation) in the coffee, which lets it extract a strong, espresso-like drink from cold water in about two minutes. ## At a glance - Grind: Fine - Water temperature: Any, from ice-cold to near boiling - Brew time: about 2:00 - Category: Cold & Iced (Immersion) - Difficulty: Intermediate - Origin: United States, 2020 - Also known as: Osma Pro, recirculating cold extraction, two-minute cold brew, cold flash ## Steps 1. **Load the coffee**: Fill the pod or basket with ground coffee and fit it in the machine. 2. **Add water**: Add water at the temperature you want, from ice-cold to hot; Osma doesn't heat or cool it. 3. **Start the cycle**: Start the brew. The pump draws water through the coffee and back into the container, again and again. 4. **Stop at your strength**: Stop earlier for a lighter cup or later for a stronger one; Osma suggests about two minutes. 5. **Serve**: Pour and drink, over ice if you like. **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. ![Chart of coffee grind sizes from extra fine to extra coarse, with fine highlighted for Osma](https://dailyextraction.com/diagrams/grind-size.svg#fine "Osma packs finely ground coffee into its basket or pod.") ## 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](https://dailyextraction.com/methods/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](https://dailyextraction.com/methods/cold-brew/):** the slow, overnight way to make cold coffee. - **[Ultrasonic cold brew](https://dailyextraction.com/methods/ultrasonic-cold-brew/):** another fast cold method using sound waves. - **[Snap-chilled coffee](https://dailyextraction.com/methods/snap-chilled/):** hot-brewed coffee chilled instantly. - **[Kyoto slow drip](https://dailyextraction.com/methods/kyoto-drip/):** the drink Roth compared Osma's coffee to. Explore every cold method in the [cold chapter](https://dailyextraction.com/methods/cold/). ## Words used in this guide - [Total dissolved solids (TDS)](https://dailyextraction.com/glossary/tds/): Total dissolved solids (TDS) measures how much coffee is dissolved in the cup, shown as a percentage. - [Bloom](https://dailyextraction.com/glossary/bloom/): The bloom is the first small pour of water in a brew, usually 2–3 times the weight of the coffee, followed by a 30–45 second pause. - [Extraction](https://dailyextraction.com/glossary/extraction/): Extraction is the process of water dissolving flavour compounds out of ground coffee. - [Agitation](https://dailyextraction.com/glossary/agitation/): Agitation is any movement of the coffee and water during brewing, such as stirring, swirling or a turbulent pour. ## FAQs ### What does Osma coffee taste like? TechCrunch describes the Osma Pro's coffee as less concentrated than espresso but not as mild as cold brew. Co-founder Joey Roth compared it to Kyoto-style slow drip with the creamier mouthfeel and brighter flavours of espresso, while admitting the comparison isn't perfect. ### How long does an Osma take? About two minutes for the Osma Pro, according to TechCrunch; WERD says about 90 seconds. The original portable Osma had a brew cycle of roughly one to two minutes. ### Does Osma heat the water? No. Daily Coffee News says the device doesn't heat or cool the brew; the temperature depends on the water you add, from ice-cold to 210°F. ### What is microcavitation? The formation and collapse of tiny bubbles. TechCrunch explains that in espresso, heat and pressure create it; Osma uses an acoustic wave to create it in cold water, which Roth credits for extracting flavour without heat. ### Who makes Osma? A small California team led by designer Joey Roth with co-founder Dan Yue, working with the founders of Chromatic Coffee in San Jose. ## Sources - [Now flowing: the Osma hot or cold recirculating brewer](https://dailycoffeenews.com/2020/12/04/now-flowing-the-osma-hot-or-cold-recirculating-brewer) - [Osma’s high-tech instant cold brew could change summertime coffee forever](https://techcrunch.com/?p=2156631) - [The Osma Pro pumps out killer cold brew coffee in 2 minutes flat](https://www.werd.com/58129/the-osma-pro-pumps-out-killer-cold-brew-coffee-in-2-minutes-flat/)