Clover Vacuum-press Brewer

The Clover is a single-cup coffee brewer made for cafés. It combines two old ideas: full immersion, like a French press, and a vacuum, a little like a siphon. The coffee steeps in hot water in a heated brew chamber; then a piston rises and the vacuum beneath it pulls the coffee down through a fine stainless-steel mesh, leaving the grounds on top. What made it famous was control: the barista can set the water volume, temperature and brew time for each coffee. Here’s how it works and its story.

The short version

• A commercial single-cup brewer.
• Immersion, then vacuum: steep, then a rising piston pulls the coffee through a steel mesh.
• Settings for each coffee: volume, temperature and time.
• Invented by Zander Nosler, bought by Starbucks in 2008.
• Relaunched as the Clover Vertica in 2022.

How does the Clover work?

1. Settings. The barista sets the water volume, temperature and brew time for the coffee.
2. Steep. Freshly ground coffee goes into the brew chamber, hot water is added and the barista stirs. The coffee steeps fully immersed, as in a French press. Houstonia reported that the chamber is heated from all sides to hold the brew within 1°F of the set temperature.
3. Vacuum press. The brew chamber is also a piston, sitting on a filter. When time’s up, the piston rises “like an inverted French press”, as Houstonia put it, creating a vacuum underneath that pulls the coffee down through the filter into the cup.
4. Serve. The spent grounds are left on top of the filter, to be wiped away, ready for the next cup.

The patent, US 8,794,127, now assigned to Starbucks, names Zander Nosler among its inventors and describes the machine as automating the steps of the French press. It describes the filter as layers of stainless-steel mesh, the top layer with holes of 30–150 microns, typically 70 microns. Because the brew is controlled precisely, each coffee can be brewed the way its roaster intends, and repeated cup after cup.

A short history of the Clover

• Before 2008: Zander Nosler founds the Coffee Equipment Company in Seattle to perfect a single-cup brewer, drawing on research into a commercial machine he’d worked on at the design firm IDEO. The earliest patent filing behind the Clover dates from 2005. Specialty cafés such as Stumptown buy Clovers; one Portland paper reported their price at around $11,000.
• 2008: Starbucks announces it is buying the Coffee Equipment Company and its Clover technology, and the Clover stops being sold to independent cafés.
• 2013: Starbucks announces plans to put Clovers in more than 1,000 US stores, but Daily Coffee News says the plan “never came to fruition”.
• 2022: Starbucks announces the Clover Vertica, which it says combines vacuum-press technology with precise control of water temperature and brew time. It needs no paper filters, grinds and brews a cup in about a minute, and offers up to six coffees.
• By 2025: Starbucks’ 2022 plan was to have the Vertica in all its US company-operated stores.

What does Clover coffee taste like?

Because it filters through fine stainless-steel mesh rather than paper, more of the coffee’s oils reach the cup than with a paper filter, as with other metal filters. The real point, though, is consistency: the same coffee, brewed to the same settings, every time.

Clover vs other brewers

	Clover	French press	Siphon
How it brews	Immersion, then a piston-made vacuum	Immersion, then press	Vapour pressure, then vacuum
Filter	Stainless-steel mesh	Metal mesh	Cloth, paper or glass
Control	Programmed per coffee	By hand	By hand
Where	Cafés	Home	Home and cafés

General guidance only. The Clover is a commercial machine, used by trained staff following the maker’s instructions.

Clover vs other methods

• Siphon: the vacuum pot that inspired many café brewers.
• French press: full immersion with a metal filter.
• Alpha Dominche Steampunk: another programmable café brewer.
• Automatic drip: filter coffee by machine.

Explore every machine method in the machine chapter.