Corey Vacuum Brewer

Back before automatic drip dominated the coffee scene, the most common brewer in kitchens, diners and doughnut wagons was the vacuum percolator. While the vacuum seems like a complicated method, it is actually quite simple, although it’s hard for me to imagine how anyone thought it up.

How does it work? — The vacuum is a bad name, because the vacuum part doesn’t come unit the end. The idea is this: water is boiled in a lower half. As it reaches boiling, a stemmed upper half is inserted. The steam in the lower half expands and pushes the water up through the tube, through a filter and into the upper bowl. This upper bowl contains ground coffee. After a minute of contact where the hot water and ground coffee mix together, the lower half is removed from heat. As the lower bowl cools, this causes a vacuum to form and it drags the upper bowl’s freshly brewed coffee through the filter, down the tube and into the lower bowl. When that’s finished, the upper bowl is removed and you now have a nicely extracted pot of coffee.

Vaculator's propriety clip-in ceramic filter

Vaculator’s propriety clip-in ceramic filter

Stainless steel spring filter

Or do you prefer this stainless steel filter

Silex glass rod filter

Or this Silex glass rod filter

There are electrified automatic versions, but they work in principal the same way. A second method places the two bowls together from the start, but I prefer putting them together only once the water reaches boiling because I want the water kept away from the grounds until we begin timing the contact time.

Temperature — The vacuum virtually automatically brews at between 195 and 205 Fahrenheit. Even though the water is boiling when you place them together, once the water rises through the tube and begins mixing with the ground coffee, it is usually at 205 or lower. Many people assume its boiling because the water bubbles as it mixes with the ground coffee. This is simply air escaping from the lower bowl, not boiling. Historically, there is evidence that the Coffee Development Group created its standards by observing a vacuum maker, which was very popular at the time.

Time — The time is user controlled, or at least user affected. A certain amount of predictive engineering is expected. You remove the brewer from heat after one minute in hopes the brewed coffee will take three minutes to descend back into the lower bowl, bringing the contact time to a four minute total. This is perfect for a fine grind, and if you use an old supermarket grinder, there will be a setting marked vacuum or “glass” and this is the setting for a four minute extraction.

This is wonderful…when it works. I’ve used vacuum brewers for fifteen years and I can say that 90% of the time, that’s just what happens. But, if there’s any micro gap in the seal between the bowls, if the filter gets clogged with too-fine coffee or for any other atmospheric reason, there is always a possibility of a standstill as the coffee stops descending. Once it’s stuck there are a number of possible fixes. Sometimes I just have to start over. This isn’t very often, but often enough to acknowledge it here.

Extraction — There is no more thorough extraction method known to me than the vacuum. All the grounds are completely submerged in a very short time period and the bubbling water seems to add what is sometimes called turbidity. It’s the idea that fapidly moving water facilitates extraction. Whether this is provable scientifically or not, it sure seems to work, enough so that the vacuum is always my brewer of choice whenever I get a light-tasting coffee. If the vacuum won’t bring out it’s notes, my view is that no method will.

Spent vacuum grounds


Spent grounds show just how effective vacuums are at
extracting every last drop of coffee flavor.

Taste — The vacuum does best with high-acidity coffees. It’s high temperature, that stays high throughout extraction, is just the ticket for light roasted coffees. I found it nigh perfect for Allegro’s Mexican Chiapas and its spicy notes. Armeno Coffee roasters has a number of light roast coffees that performed splendidly with the vacuum, where I was detecting a slight sourness when these same coffees were brewed using a Chemex. The coffee is, if anything, too hot when brewing is completed. If you really like hot coffee, this is your method. I simply use it as a great opportunity to clean the upper bowl while waiting for my cup to come to a reasonable drinking temperature.

Filter notes: No method offers a greater range of filter choices than the vacuum. This particular vacuum, purchased off eBay, features Vaculator’s proprietary ceramic filter held in place by stainless steel clips. The idea, as with glass rods, is to offer a slightly bumpy surface that, when placed in contact with a glass or metal bowl, allows the liquid to pass through, but little or no particulate. You end up with something in between the thick almost-unfiltered French press brew and the cleanness of automatic drip using paper filters. Some would say it’s the perfect compromise. Meanwhile, there are still cloth and paper filtered vacuums as well as a metal spring type that used to be the standard in restaurants. All allow some sediment except for paper.

Cleanup — The vacuum is slightly easier to clean than a French press. While there’s no press to disassemble, there are grounds to either wash down a sink or transfer to waste or, best of all, a compost bin. The worst attribute of the vacuum is the fact that the upper bowl must be removed while it’s still piping hot. If it’s glass, there’s an increased risk that it will break. I’ve broken more than one. Metal ones won’t break, but the hot part is still awkward. There are some ingenious answers to where to put the still-hot, still-grounds-filled upper bowl. A metal one can be laid on its side. The grounds are usually so drained of coffee that they are like a solid mass that will stay put until you clean it.

Conclusion — If you’re looking for the ultimate extraction experience, this brewer may fill the bill. It is not hard to use or clean. The biggest time challenge is waiting for the water to heat up on a stove, or hot plate. Sometimes, I split the water and transfer some to a separate tea kettle to boil, but that’s more trouble than you probably want to go to. If you’re in a hurry, there are other methods that will be more appealing. Even if it happens once, you won’t soon forget a stalled vacuum as described above. Waitresses used to wrap cold towels to attempt to induce the vacuum to cooperate and release the coffee to its lower bowl.

In short, it’s a wonderful method, but I would want another machine as a primary or backup one.

Technivorm 741

I originally reviewed this brewer’s predecessor in The Coffee Companion many years back. When I received its newest revision of the basic design, I was eager to see if my previous knock against it had been addressed. It has and read on to discover a coffee industry favorite.

When traveling to shoot interviews with eight coffee notables last year, I found a Technivorm (pronounced: Teck-knee-form) in almost every location. Many top coffee honchos have a Technivorm as their primary auto-drip machine. As Ian Bersten said to me, it’s an example of good engineering carried through manufacturing without compromise. Good design, good parts. It all seems so easy it’s hard to understand why most big coffee companies haven’t simply reverse engineered the Technivorm into their standard design.

In fairness, the Technivorm is not the only way to make a good auto drip machine. It is also not the only one made. One company, Presto, all but did build a “cheaper” Technivorm and it came and went in a flash. Apparently, the coffee literati overlooked the Presto, possibly as too good to be true. To be fair it did some things with less aplomb, but others with more, but consumers, even so-called leading edge ones, missed it.

So, we’re back looking at the Technivorm 741. What does it do that’s so spectacular? Well, it quickly heats the water to 200 degrees Fahrenheit and sends it through the grounds in less than six minutes, achieving the main technical specs of the Specialty Coffee Association for drip brewing. It does this using a good thermal heating block. Its water tubing is wide and unforgiving. I’ve owned its earlier version since the late 1980s and it’s never “limed up”, even though I use hard water and rarely clean it.

If the Technivorm has a weakness, it is its ability to shower your precious grounds with its perfectly heated water. The earlier version had a single hole the water dripped from, and I noted this in my first review. Technivorm responded by drilling several smaller holes over a still-limited space, but, frankly, it only improves its spread slightly. I still find myself removing the loose-fitting cover and stirring the grounds during brewing in order to ensure all the grounds participation.

Improved multiple sprayhead or not, you still should stir during brewing.


Improved multiple sprayhead or not, you still may benefit from starting the brewer for a full minute, shutting it off for another minute, allowing the grounds to rise and settle. This extra step can make a significant difference in the ability of the Technivorm to fully saturate and extract from your entire grounds bed during brewing.

The first version made 8 4.5 ounce cups — that’s 36 ounces. The current version makes 10 4.5 ounce cups — 45 ounces. Generally, this new amount is about perfect for three or four friends to enjoy a couple of American style coffee cups together. When it’s just two of us, I prefer to use the smaller, earlier version. They brew identical cups. I timed the brewers and the new one is slightly faster, just enough to make 8 cups as fast as the older one made 6 cups. That’s exactly as it should be.

Technivorm added a new feature to the larger model, which indicates an ability to make a 1/2 batch, by partially closing the exit valve at the filter basket’s bottom, slowing the coffee’s release. After playing around with this feature for the past few years, I find it does a credible job allowing you to truly make a 1/2 batch that tastes identical to a full batch. In my tests, you can make a comparable 1/2 batch filling up the the 6-cup water line and using 36 grams ground coffee.
Drip coffee makers are always optimized to make a full batch. With some (Bunn comes to mind) half batches are all but impossible. Most consumers see owning a second machine for smaller batches as a luxury, but if you, like me, often make coffee for just two people, I generally recommend a second machine. Technivorm’s offering a half-batch feature that really works is a significant advantage.

Filling from the bottom up this funnel top makes sure everyone gets an equally full-flavored cup

The Technivorm has a slightly eccentric habit of having a small amount of water remaining after brewing. I’ve never noticed a problem nor any negative side effect, and if it bothers you, simply wait a few minutes for the brewer to cool down and turn if upside down over the sink or a glass and the water will spill out. It’s about a tablespoon’s worth. I used to do just that, but more often I just forget about it.

There’s a demonstration of the Technivorm done by TerroirCoffee.com’s George Howell on my Coffee Brewing Secrets DVD. George wets the filter before brewing, as a preventative of any filter taste getting in the way of the coffee taste and as what another friend called good laboratory practice. I met Gerard-Clement Smit, the Technivorm’s designer, who seemed perplexed that anyone would do this. I’ve tried it both ways and haven’t detected any taste difference, and it’s nothing about the Technivorm. If you accept the need to do it, it should be done with any paper filter coffee brewer. This brings us to paper filters. George Howell further mentions, and I agree with this, that paper filters offer arguably the best way to make coffee with the viscosity of wine, with all the important oils, but none of the particulate. If you want to use a mesh filter with this brewer, I’ve seen them from SwissGold and other manufacturers, but I personally find the balance and mouthfeel just right with the paper filter. Don Schoenholt used a metal filter with his Capresso drip brewer and he prefers the slight amount of sediment, which admittedly, is a small amount. If you like French press-style gobs of sediment, you’re not going to get it using autodrip with any filter I’ve tried. Plus, the press brewing temperature and brewing stillness is going to deliver a different tasting cup with or without sediment.
The absolute middle brewing temperature of 200 degrees, the 6 minute contact time and paper filter work to give you an auto-drip coffee brewer that works well over a wide range of coffees. The brew temps are high enough to deliver acidity with lighter roasts, but just about any coffee I tried came out fine. I might prefer a slightly lower temperature for Peet’s aged Sumatra, but Allegro Coffee’s Sumatra Mandheling (ask for the Mandheling, different from the Organic Fair Trade) was excellent.

I used up to 72 grams of medium-fine grind coffee to make a full batch, the rough equivalent of the 65 grams I used in the older/smaller Technivorm. Recently, after a lot of tests with an assortment of friends drinking the Technivorm coffee, I’ve found I can back off to around 60 grams for a full batch, which is my recommended start point.

Conclusion — If you’re looking for a long-lived simple automatic drip coffee brewer that makes 10 4.5 (just shy of 8 regular/6-ounce cups) of coffee, the Technivorm should be at the top of your list. It retails for nearly $300, and its only potential caveat is you might need to stir the grounds to ensure the best extraction.

Speak and Brew Coffee Maker: It can talk to you, but can it brew?

The Audi Roadjet with coffee maker. What's worse: Useless coffee makers or useless coffee maker features?

The review of the Speak and Brew coffeemaker will depend upon the willingness to send one to me because I actually test coffeemakers. This is true for the Audi Roadjet a concept car with built in coffeemaker too. I put measured ground coffee in them, press the button and brew. While it’s brewing, I take the water temperature as it cascades down through the grounds. I time it to make sure it brews for the proper amount of time and, yes, there is an ideal time, or at least a range of times.

My purpose if writing of this is there are so many coffeemakers that try to achieve greatness by doing everything imaginable… but brew good coffee. I’m not against these features. The ability to speak to me might be important. Let’s say I’m married to a very chatty spouse and I never get a word in edgewise (I’m not, but we’re just “let’s say’ing”). Or let’s say I’m single and want a little conversation. Well having a coffeemaker that speaks to me might be pleasant. Of course I start thinking of the machines that speak to me in my life: my GPS speaks to me. But, it rarely says anything except barking orders at me, or correcting me if I make a wrong turn, more often a turn it doesn’t know about that involves a shortcut.

A coffeemaker with a clock in it seems like a good idea, but is it? The coffee isn’t as good if you grind and set it up the night before because flavors are released into the air, but I agree it might still be worth it. Of course I can do all this except press the on button the night before with any regular coffeemaker.

But, there are legitimate conveniences I truly wish would work, such as on-board grinders. These almost never are good grinders, even the burr grinders. And, they are difficult and sometimes impossible to clean. And still, the brewing needs to be right.

I’ve been looking over reviews for the past years. I can’t find a single all-in-one coffeemaker that is in the top rank. If it did, I’d almost guarantee it would be a bestseller. But, there isn’t and that’s the truth. Is it that they don’t know? Has the SCAA and various authors and coffee experts done such a poor job of teaching the brewing basics?

I suspect the answer is the manufacturers of such machines automatically presume the enduser of such gear has no interest in anything but the gimmick or feature. Or they feel that by being the single player that satisfies this particular need they no longer need to try to do it all.

But, I wish otherwise. I genuinely like gimmicks. I like extra features. I simply wish a machine with extra features would also make good coffee.

Zojurushi 5 Cup Coffeemaker Review

Zojurushii coffee maker, zutto coffee maker, zojurushi reviewThe Zojurushi 5-cup coffeemaker attracted my attention at a previous International Housewares show. I’d been trying to find a successor to the legendary Kitchen Aid 4-cup. Could this be it? My appetite was whetted when I ran into it again at Oren’s Daily Roast. I practically begged him to let me try it, but I’m already into him for so much coffee, he put me off. Finally I got the courage to scarf one from their sales rep at this year’s Housewares show. I was pretty excited to see it. It has the second most important virtue of any coffee gear, good looks.

The 5-cups are to me really four, but that’s what I’m looking for.

Number one, though, can it brew great coffee?

I finally scarfed one off Zojurushi’s PR people who I met at the International Housewares Show. One showed up on my doorstep a few days later.

It uses a number 2 Melitta filter. It has a removable water chamber and an inline charcoal filter. I was surprised that the filter appears to be located after the water is heated. As I use mostly low-mineral no-chlorine water I hardly need such a filter. No mention is made in the instruction book as to where to buy replacements.

Using the Zojurushi is easy. Fill the water tank up to the line. The instruction book may be light on the water filter replacement but it is excellent about its suggested formula, specifying 35 grams of fine grind coffee for a full pot. That works out to the industry formula. This might not seem astounding but recipes are almost never mentioned in coffeemaker instruction manuals, and when they are, they are usually wrong.

Monitoring the brew temperature showed me what I wanted to see. It really gets hot, not quite as instant on as the Technivorm, but very close, 200 degrees Fahrenheit for most of the brew cycle, even a little above towards the end. Best of all, the water gets all the grounds nicely wet. It’s a little appreciated fact that the biggest advantage manual drip has over auto drip is your hand always knows where to pour hot water. I found the best way to ensure this is to remove the top during brewing; I presume this is because the lid must be located precisely, but it’s easy to try it once and see if you agree. With minimal futzing, this coffeemaker just works almost perfectly.

Result? After years of searching I’m done. The Zojurushi does a stellar job, almost the equal of the Technivorm in temperature and actually, gasp, a little better in its drip performance. You almost can’t do better yourself.

Recommendation? Place 35 grams fine grind coffee for a full pot. Flip it on and in seven minutes, you’re ready to enjoy. Seven minutes may seem overlong to American drip aficionados, but trust me you will like the coffee. I ascribe the slightly longer contact time to Japanese fascination with European standards (I’m half-kidding) and the fact that during the first minute the water is just under ideal brewing temperature.

I brewed several batches of Bridgeport Coffee Company’s El Salvador Finca Las Nubes – Ernesto Lima. They charge for heirloom bourbon coffee grown by the kind of farmer who walks around dusting his plants every afternoon and, using this brewer, I could taste it. I then brewed some very different Oren’s Daily Roast Viennese Blend, which is make up of two stellar Colombian coffees, one light and the other French roast. It’s my favorite summer after-dinner coffee. I get a lot of local produce during the summer months and this coffee is able to add to a meal already chock with rich flavors. This brewer actually made coffee virtually identical to what I could do with a Hario V60, no mean feat.

This review has a simple ending: Zojurushi is top rated, the current five cup champ.

Sowden SoftBrew: A Brewer Disguised As A Teapot

I got this interesting coffee maker from Oren Bloostein. Oren suggested this might appeal to some folks as an alternative to the French Press or press pot as it’s becoming more widely (if generically) known.

And, it is innovative. It features an attractive ceramic pot, and a patented inner cylinder. You simply place grounds in the cylinder, (more…)

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