How the Clover Coffee Maker Works

The flavor of your coffee depends on two things -- how the beans are roasted and how the drink is prepared. Roasting packs the flavor potential into a coffee bean, while grinding and brewing prepare the beans in a way that maximizes the flavor. The Clover gives you control over the two brewing factors that affect the flavor, which are the temperature of the water and the dwell time, or the time in which the grounds are in contact with the water.

The Clover uses a proportional integral derivative (PID) controller to create the exact right temperature of water every time. Even a change of a few degrees in water temperature can make the difference between a cup of sludge and a cup that highlights the flavor of the bean. If the water is too hot, it will overextract the flavor of the beans, resulting in a bitter taste, but if the water is not hot enough, then you have underextraction and a weak cup of coffee.

This coffee maker also lets you dial in the exact number of seconds that the grounds are in contact with the water, and the Clover's brewing process is designed to bring out the best in the grounds. Let's look at how it compares with other coffee-making methods.

Most people have an automatic drip coffee maker on their kitchen counter -- it's fast, easy and gets them going in the morning. Unfortunately, the drip coffee maker is not going to win any awards for how the coffee tastes. These makers don't heat the water enough or allow the grounds to interact with the water for long enough to make the perfect cup of coffee.

T­o get the best-tasting coffee, coffee experts have long agreed that you have to use a French press or a vacuum brewer. Both of these methods allow for more control of the water temperature and the brewing method than an automatic. To make coffee in a French press, the grounds and almost-boiling water steep for several minutes. The top of the French press has a plunger that's attached to a mesh filter. When you push down on the plunger, the screen separates the brewed coffee from the grounds. The grounds are pushed to the bottom, and coffee is poured out the top.

Vacuum pots are named for the air vacuum that's created between its two connected globes to draw down the brewed coffee. The bottom globe is placed on heat, which warms the water within it. As the water heats and expands, the resulting water vapor creates pressure that forces the rest of the water into the top globe, where the ground coffee awaits. The vapor also moves up, which heats the water and the coffee and agitates it for a good brew. When the bottom globe is taken off the heat, everything that rose up must now come down, so the brewed coffee, minus the used grounds that are caught by a filter, fills the bottom globe.

What does this have to do with how the Clover works? Well, the Clover uses the best of both methods with its patented VacuumPress Technology. The brewing happens in a steel brew cylinder that sits atop a piston. When the brewing process starts, the piston moves to its lowest position and a drain valve at the bottom of the machine closes. After the coffee steeps, an actuator forces the piston to rise with the used grounds held by a perforated mesh screen, almost like a French press in reverse. When it does this while the drain valve is closed, a vacuum is created that draws down the brewed coffee. The piston descends again, the drain valve opens and the coffee enters the waiting cup.

We'll take a look at what else goes into brewing Clover coffee next.

You might have gotten the idea that the Clover is an unattractive mix of pistons and valves, but it's a sleek-looking machine that makes coffee brewing pretty fun to watch. The Clover, despite the snazzy VacuumPress Technology and PID controllers, still needs the help of a gifted barista. Let's look at how Clover coffee is brewed, from start to finish.

We're not starting with instant coffee with a Clover, as we mentioned before. Likely, the café customer has a few whole beans to choose from, and hopefully, a knowledgeable barista to guide the choice. Let's say the customer picks some beans from Kenya and would like an 8-ounce cup of coffee. The barista will likely have a tip sheet, fine-tuned by Clover and the coffee shop owners, which will contain the Clover specifications that will produce the best cup of coffee with this bean. On the front of the Clover is a knob that allows the barista to change the settings, plugging in the cup size, the time that the coffee should brew and the temperature of the water.

The barista doses, or measures, the beans, and then grinds them fresh. Human error or a faulty grinder could actually screw up the perfect cup of coffee that the Clover promises. The size of the grind affects how much flavor can be extracted. It varies from bean to bean and is dependent on how long the coffee will brew.

When the coffee is ground, it's poured into the brew chamber at the top of the machine. As we mentioned in the last section, this is basically a filter atop a piston. Behind the brew chamber is a water boiler, and the water pours from a spigot into the chamber. The barista stirs the mixture, ensuring that the ­grounds are thoroughly moistened. This is the other step where human interaction can affect the taste of the coffee; debates rage on barista message boards about the best way to stir the grounds. The stirring ensures that the grounds are completely wet and helps to extract the flavor from them.

Then the brewing begins. What someone can see from the outside is the top of the bubbling coffee rising and falling, but as we learned in the last section, pistons are rising and falling, grounds are being pushed up and coffee is being sent out through the valves. The whole thing is over before you know it -- brewing takes about 40 seconds [source: Clover]. Up top, the grounds form a cake that can be easily wiped into the waste bin at the top of the machine.

Quick brewing and easy cleanup are two of the selling points of a Clover, especially in comparison to the more cumbersome French presses and vacuum brewers. But even if you love your French press or vacuum brewer, the Clover is set apart by that ability to regulate so many different factors of the brewing process. Once you figure out the temperature and time that produce your favorite cup of coffee, you can replicate that experience over and over. No more having to chalk a bad cup of coffee up to accidentally overheating the water or allowing it to steep too long. For every type of coffee bean that exists, the Clover has specifications that bring out the best in it, every single time.

We keep talking about Clover's ability to make the perfect tasting cup of coffee, but what are you supposed to be tasting? Why does it matter if you brew a coffee from Kenya differently than you brew one from Sumatra? On the next page, we'll get a taste of what's going on with coffee beans.

So what if Clover makes the perfect cup of coffee? Isn't it all about getting as caffeinated as possible? Well, when you consider that coffee beans have more than 800 flavor characteristics, compared to red gawine's 400 flavor characteristics, then you might start to reconsider what's in your cup [source: Gourmet Coffee Zone]. Clover's ability to bring out this flavor could make coffee into a gourmet industry, similar to wine.

The main components of measuring coffee's taste and flavor are acidity and body. Acidity keeps your coffee from tasting bitter or sour; it's frequently described as the "brightness" of a cup, the thing that's making your tongue tingle a little bit [source: Merchants of Green Coffee, Coffee University]. Body is how the coffee feels in your mouth. Generally, the higher the acidity of coffee, the lower the body. You also evaluate the aroma and finish when tasting coffee flavor.

As we said before, the process of roasting puts this flavor into a coffee bean. Coffee beans are roasted at high heat for various periods of time; longer durations and higher temperatures lead to darker roasts. When the beans are heated, the sugars carmelize and create the oils that give coffee its taste. Generally, medium roasts provide maximum flavor. Darker roasts actually burn off their flavor more, and if the bean is overroasted it may just taste bitter.

When you buy a cup of coffee at Starbucks, you're likely drinking a dark roast, but many Clover fans think that the machine could popularize light and medium roast coffees, which have more nuance and flavor. Brewing extracts the flavorful oils from the grounds, and the factors that you can control with the Clover are some of the main drivers of flavor. These factors are the amount of water, the heat of the water and the dwell time.

A­ll of this is a long way of saying that while the Clover is famous for its yummy coffee, it's not going to turn bad coffee good. The machine helps baristas pull out the flavor that's already there, and baristas still control factors such as measuring and grinding the beans to the right size. We may just be beginning to learn what flavor can be extracted from a coffee bean, but the Clover could go a long way in helping us to extract it.

Clover coffee makers have created a class of mad scientists, replacing test tubes with coffee cups and body parts with coffee beans. Instead of trying to bring Frankenstein to life, they're searching for the perfect cup of coffee. Tinkering with the temperature or stirring the grounds a little differently might yield the ultimate brew, and then when you find it, the controls of the Clover allow you to lock it in, so that you can consistently create it.

Are you interested in a Clover so you can make amazing coffee in your own kitchen? Well, we might have forgotten to mention that the Clover retails for $11,000. Find out the market for these pricey machines on the next page.

Several hundred Clover coffee makers were sold to cafes around the world in just a few years. According to a retail coffee consultant, a coffee shop spends about $50,000 on equipment, with about one-quarter of that funding an espresso machine [source: The Economist]. Typical commercial brewers might only run $1,000 to $4,000 [source: Robison], but the built-to-order Clover costs $11,000 [source: Adams].

Is it worth it? On Clover's Web site, a profit calculator helped café owners determine if the Clover would­ ever pay for itself. Factors included the abilities to charge more per cup for better-tasting coffee, reduce wasted coffee by only making as much as was ordered and increasing sales of whole beans, as the customers were allowed to experience the bean quality before committing to the whole bag.

Clover claims that every store that charged more for coffee made with this machine was successful in doing so because customers appreciated the freshness and the flavor [source: Clover]. How much more did cafés charge? In Pittsburgh, the price ranged from $2.30 to $4.80 for 12 ounces [source: Carter]. Canada's Smiling Goat Organic Espresso Bar made news for charging $20 for coffee made with Panama Hacienda La Esmeralda beans, which retail for $130 a pound in the United States [source: Mandel].

Clover suggested to potential buyers that giving the customer a chance to sample these pricier beans might make them more likely to invest in an entire pound of them. And since brewing the coffee takes about a minute longer than pouring it from a carafe, that was time for the barista to educate their customers on what they were drinking and suggest other beans they might like. For some, that minute might be too long, especially for cafés in busy downtown environments that serve people on the go [source: Carter].

Along with the technology to brew flavorful cups of coffee, Clover also offered the technology to track what was being consumed at any given moment in a café. CloverNet is a Web-based software system that could track what drinks were brewed and who was brewing them, allowing shop owners to determine which beans were the most popular and which baristas were the most effective salespeople. CloverNet also offered the ability to input all the brewing specifications for the beans into the system, so that if a café owner had perfected a certain Ethiopian coffee, it could pull up those specifications instantly, without the barista changing the machine each time.

 One of Clover's customers was a little company out of Seattle that you may have heard of -- Starbucks. In March 2008, they announced a deal with Clover that shook the coffee world even more than caffeine. Read on to find out what the buzz was about.

In early 2008, Starbucks conducted a test run of Clover machines. Starbucks priced a cup of Clover coffee at $2.50 in Seattle stores, compared to $1.55 for the traditional drip [source: Robison]. The company must have liked the results; just a short time later, Starbucks announced it had purchased the Coffee Equipment Company for an undisclosed price. All future Clovers will appear in Starbucks stores.

For Starbucks, buying Clover is a step toward restoring a more authentic coffee shop experience. A memo from CEO Howard Schulz in 2007 admitted that Starbucks was lacking the "romance and theater" of coffee in recent times [source: Robison], but that's not the only thing lacking: Starbucks' stock had lost about half its value in the 15 months before the Clover announcement [source: Stone]. The deal came at the same time as a few other deals meant to improve Starbucks' standings, including a new flavorful coffee blend and improved espresso machines [source: Stone].

It's not clear yet how many stores will get Clovers, but for someone desperate to try this flavorful coffee, greater exposure can only be a plus. However, to the small, independent stores who adopted the Clover early on, there is a sense that the Coffee Equipment Company sold out to a corporation that causes many coffee connoisseurs to turn up their noses.

Clover fans worry that the emphasis that this machine provides to the individual and to each cup of coffee will be lost in busy stores, despite Schulz's desire to bring back romance and theater. While the Clover can be programmed to deliver a consistent cup of coffee, it's still a barista-managed machine, and changing the programming of some brews requires some know-how. Will the coffee scientists that love tinkering with Clover specifications still have the chance?

One independent coffee shop, Stumptown Coffee in Portland, Ore., announced that it would get rid of its Clovers rather than cut a check to Starbucks for repairs [source: Gunderson]. There's even some speculation that existing owners might not be able to get much more than that out of Starbucks. While Starbucks will honor existing warranties and provide parts, it's uncertain how long that will last, and there will not be any further training for existing owners [source: Price].

Most important to a coffee shop that was using the Clover to track sales and earnings, CloverNet also became the property of Starbucks. Existing Clover owners were scheduled as of press time to lose access to the software in mid-May 2008, though Clover promised to back up the store's data and provide them with a copy.

One coffee analyst saw Starbucks' purchase of Clovers as less about competing with independent coffee shops and more about striking out at McDonald's and Dunkin' Donuts, who have increased their coffee and espresso offerings in recent months. Using Clovers allows Starbucks to corner the market on "fresh coffee," since it's made a cup at a time and on the spot. Since "freshness" is a powerful marketing concept (indeed, it'd be difficult to find someone who desired something stale), Starbucks has a lock on being able to guarantee this desired trait to its customers [source: Price].

In an e-mail to the New York Times, one of the founders of the Coffee Equipment Company acknowledged that frustration and resentment are to be expected on the part of the early adopters of the Clover. At the same time, he said that he's also sensed excitement from people for what a Clover in every Starbucks could mean for coffee lovers [source: Meehan]. So if you're serious about coffee, it might be worth keeping an eye out for Clovers in Starbucks…it might just be a luckier find than a four-leaf clover.

More links about the Clover and coffee are brewing on the next page.