When talking about iced coffee, one will generally encounter two schools of opinion when it comes to the best brewing method: hot or cold. Neither method is necessarily “correct,” and preference depends entirely on what you are trying to get out of the cold brew experience. Brewing hot, as in the Japanese iced method, tends to preserve more of the delicate fruit and citrus tones and is well suited for highlighting the top notes of a high grown African coffee. Brewing cold, on the other hand, minimizes a coffee’s acidity (the fruit, floral, and citrus notes), and allows a coffee’s natural sweetness to show through.  A Brazilian or Indonesian coffee brewed on the Yama Cold Brew Drip Tower would be both crisp and sweet with a neutral acidity.  The only downside is that this process takes 8 hours to complete, but the reserved acidity is well worth the time for many.

This difference in flavor presentation is almost exclusively a result of extraction temperature.  A higher temperature will more completely dissolve a coffee’s sugars and volatile oils, but it will also coax out more of its acid qualities. When cooled slowly, these sugars tend to turn rancid and sour. The secret to preserving these flavors is brewing hot and chilling the coffee instantly. Doing so dramatically inhibits oxidation and keeps these delicate flavors in balance, but the heightened acidity can be unflattering, which is why the Yama Cold Brew Tower has such a fervent following. The benefit of the Japanese method, however, is that it is much more accessible and can be brewed on conventional equipment. For those with a V60, Chemex, Bonavita, or Technivorm at home, you can get double use out of it during the hot summer months. We just need to compensate for brewing over ice. Below are a few starting points to get you on your way.

Want to read even more geekery? Check out the original discussions of James Hoffman,  George Howell, Oliver Strand & Peter Giuliano.

E61 Brew Group on the Izzo Duetto II

As we wait for the Rocket R58 to join the Izzo Duetto II in our office later this month, I thought perhaps now would be an opportune time to examine just what these double boiler E61 machines are bringing to the market.

The E61 Brew Group has been hailed as the industry standard  since its inception by La Faema in 1961, but it has steadily been overtaken in recent years by the newer Saturated Brew Group design. The brewing group is open to the brew boiler itself in saturated groups, which results in improved temperature stability due to the group being saturated with the same body of water whose temperature is being controlled in the boiler. This design is only possible, however, with machines that have separate steam and brew boilers such as the La Marzocco GS/3 and La Spaziale Vivaldi II series.

Before saturated groups were invented, almost all espresso machines could be found utilizing some variation of the original E61 group head, despite it being a 50 year old technology. Interestingly enough, dual boiler systems are now coming out that utilize the older E61 design, the Izzo Alex Duetto II and Rocket R58 being perfect examples. Both machines, in fact, are completely PID controlled, a modification that is not possible with traditional E61 heat exchangers.

Although the E61 has been superseded by saturated groups in high-end commercial use, their temperature stability and tried and true design, especially when combined with double boilers, make them an excellent choice for use in a low volume, home environment. With this being the case, what choice are you actually making when choosing between the two brew group designs?

Saturated Brew Group on the La Marzocco GS/3

Before independent brew boilers were available, the E61 group achieved thermal stability through the eight and a half pounds of chrome-plated brass that it was physically molded from. This is the reason why the brew group takes around 30 minutes to both heat up and cool down. Even though the group provides a thermally stable environment at the head, the user still has to compensate for the relative unpredictability of the actual heating element within the machine. Users of a heat exchanger are well aware of the necessity to bleed the group prior to pulling a shot in order to reduce the temperature of the water within the system. As you continue to pull shots, the water will steadily deviate from the optimal temperature range and eventually exhaust itself. A saturated group, on the other hand, pulls water from a dedicated and thermally controlled water source. Depending on the size of the boiler, the water should remain at a consistent temperature over the course of multiple shots. Double boiler machines have quickly become the industry standard for this very reason.

We will soon be conducting thermal stability tests between the two designs. We’ll post results when we have them. Unlike saturated groups, which often require a warming flush in order bring the head up to temperature, the E61 is always idling at temperature. Theoretically these machines should never need to be bled when combined with a dedicated boiler, which would result in an increase in shot workflow and quality when viewed from a stability standpoint. Whether the operator is aware of these ramifications is another issue entirely.

While specific engineering aspects of these two systems is beyond the scope of this article, there are several excellent threads on Home-Barista that explore both the E61 and Saturated group systems.

I had a chance to test out the Able Disk Fine recently, and I found it to mark a significant departure from previous iterations in both design and cup quality. I am particularly impressed by the fact that the filter produced such a clean and complex cup, despite being a metal filter. It is quite apparent that care was taken in its design to more closely mimic paper.

For those that have been skeptical of pairing the Aeropress with a metal filter, I would highly recommend giving the Disk FINE a try. The significantly tighter hole distribution yields a surprisingly clean cup that still retains the complexity of a full immersion brew. The Water Avenue El Salvador I brewed was both full in mouthfeel and vibrant in its starfruit acidity.

The physical etching of the holes is also much more precise, but the resulting filter is thinner. I believe this newfound pliability actually works to its benefit, however. The Disk springs back if folded, and it adheres like paper when wet. This is definitely a benefit to those like myself who are prone to bending or losing the filters when in a rush.

One can only hope to see an equal leap in quality in the soon to be re-released Coffee Kone.

Izzo created a lot of buzz last year when they released the Duetto II, and for good reason. It was the first machine of its kind to offer a commercial E-61 group head, double boiler, and fully integrated PID control for precise temperature control. Now there’s another machine with similar features. We always favor more more options for the home barista, and we think this machine will be a good alternative to the Izzo Duetto. The addition of a dual pre-infusion system in the Rocket R58 espresso machine makes achieving a smooth coffee extraction with optimum aroma, body, and crema an even more achievable reality for the home barista. This feature in itself makes the Rocket R58 a strong contender in topping the list of home double boiler machines.

The 1400 watt heating element in the brew system is exceptionally quick to recover, allowing you to pull shots and steam milk at optimal temperature and pressure without lag or overtaxing the machine. The rotary pump is both quiet and smooth, and, for those really wishing to dial in their espresso, the brew pressure is easily adjustable from the exterior. The machine is also equipped with low water sensors and an easy to lift top cover, so you can effortlessly check on and fill the ample 2.5 L water tank. For those that have the space and ability, the R58 also has the option to be directly plumbed to an existing water line.

We will be doing a video review of this machine shortly. They are expected to arrive in the US in late May, so reserve yours today!

There is something to be said about simplicity and tradition, and the new Sowden brewer returns to the basics of coffee preparation with its beautifully simplistic design. I spoke with the folks at Sowden at the SCAA conference this past week, and I was impressed by the ease of use of the process that they have termed “soft brew.” At it’s heart, the Sowden is a full immersion brewer, and the basic process for brewing is quite similar to that of the french press. What makes this particular brewer unique, however, is its finely etched metal filter. The resulting cup is much cleaner than that of a french press, yet you retain more of the delicate oils for added depth. When you are done extracting, the filter is removed from the porcelain server, which saves you from the worry of over-extraction.

The Sowden can also double as a tea infuser or a cold brewer – a definite bonus.

HOW TO BREW ON THE SOWDEN:

The basic process for the Sowden is quite similar to that of the French Press.

1. Put your kettle on to boil.
2. Pour about 8 ounces of hot water through the filter and carafe to preheat
3. For a 12 oz cup, grind about .75-1.25 oz of coffee beans to a medium-coarse setting.
4. Once your water is boiling, let is rest for a bit so the temperature can go back down to 200 degrees.
5. Infuse your coffee grounds with 12 oz of hot water. The grounds will start to “bloom.” Let the blooming grounds sit for about 1 minute.
6. Stir to break down the bloom and re-wet the top layer of coffee.
7. Remove the filter after four minutes and place it into a separate container to finish draining. Once you’ve made a pot or two you can adjust for your own palate.

We were thoroughly excited when we received Bonavita’s Electric Gooseneck Kettle last year. Finally, there was a stainless steel electric kettle that was suitable for manual pour-over. When we heard that Bonavita was coming out with a kettle with a variable temperature control, we were anxious to get our hands on one.

At its heart, the variable kettle is essentially the same as Bonavita’s standard electric gooseneck kettle. It can heat 1 liter of water in 5 minutes, which is slower than other variable kettles in the market, but you are gaining the gooseneck spout, which is essential for maintaining a constant water flow with manual pour over styles. The kettle pours smoothly, though the handle is not as ergonomic and comfortable in the hand as the stovetop model.

The brains of this kettle which gives you variable temperature control is well designed. You can continuously monitor the temperature via the digital display and adjust your target temp on the fly in both Fahrenheit and Celsius. In our tests, we found the reading to be accurate to within .5 of a degree. The kettle will also maintain the hold temperature for up to 20 minutes, making it especially appealing for café use.

A nice addition is the ability to save 6 user pre-set temperatures. This is perfect for those wishing to brew both coffee and tea, or for those wishing to experiment with coffee varietals and temperature profiling. The kettle uses solid state memory to record your presets, so unplugging the kettle won’t mean dialing everything in again the next time you use it.

Every product has its drawbacks, and my main complaint is the relatively low build quality of the heating base. I would expect it to break down eventually if used in the bustle of a high volume environment. For a variable kettle under $100, however, this does not come as much of a surprise. Another issue for some will be the short power cord of 24 inches. A retractable and longer power cord would be a welcome addition. Unless the kettle is sitting directly next an outlet, it might be a struggle to reach an outlet on a cluttered counter.

In the end, the Bonavita Variable Kettle is both well thought out and intuitive to use, and, being commercially UL certified, I would recommend it for both home and professional applications.

Check out the Bonavita Variable Temperature Kettle.

UPDATE: Bonavita sent a note that the unit I tested was a pre-production sample, so the unit shipping in July will have some tweaks and upgrades to the fit/finish. I may have to rescind my comment about heavy duty use. We’ll post an update once we receive the production units in July.

UPDATE 2: I only tested the kettle for 20 minutes, as the manual said it would hold temp for 20 minutes. I was recently advised that it actually will stay on for 60 minutes. I retested and can vouch for this!

In your research, you will find that multi-purpose grinders such as the Breville Smart Grinder, Baratza Virtuoso, or the all-manual Hario Skerton are well suited for a variety of brewing methods, whereas a dedicated espresso grinder such as the MACAP or Mazzer Mini are much more specific in application. With such a large marketplace, understanding your favored brewing process and pairing it with the right product is possibly the most important step in achieving your desired cup.

While we certainly don’t expect you to fully acquaint yourself with all of the technical details of your equipment, we do hope to help guide your understanding of the options available to you so that you can avoid having to reinvest in 5 or 10 years because you chose “too little” or “too much” of a grinder.  Just as a  blade grinder is not a good match for an espresso machine, the Mazzer Mini would not be a good match for a drip brewer.

You will notice that we have decided to offer only burr grinders. Uniformity of the grind is perhaps the most crucial element in achieving a full and sweet cup of coffee, and a blade grinder simply does not offer the finesse needed to bring out the subtle flavors found in coffee. Blade grinders chop beans into unevenly sized particles. Burr grinders both cut and crush uniformly. In the case of espresso extraction, where even the smallest of changes in grind can have drastic affects, a burr grinder is an absolute necessity. For other brewing methods, burr ground coffee provides more body and character to the finished cup. Not every grinder is the same, however, and the nuances of each will lend you a different result.

Conical Vs. Flat

Conical burrs have a greater cutting surface than flat burrs and can therefore rotate at a slower speed. Slower grinding speeds will not only reduce noise, but will also reduce issues with heat and static buildup in the grinding and dosing chamber. Coffee is very sensitive to heat, and it is possible to “bake” your coffee if your burrs are excessively worn or if the cutting surface is too small for the amount you are grinding.  Static also promotes channeling and bitterness in espresso due to grinds clumping. Conical grinders are also thought to produce a tighter and more uniform grind by crushing the bean rather than shearing it, which can cause an unwanted abundance of very fine channeling particles.  This design of conical burrs, however, make them much more expensive and difficult to produce.

The primary difference that you will find is number of adjustments allowed by each grinder, and your need will vary depending on how you wish to use it. For most home users, 10 to 40 adjustment settings will be plenty, especially for a Technivorm brewer or French press. However, if you are considering pulling espresso as well as brewing in, say, a press, it would make sense to think ahead and purchase a grinder that has the capability to do both. Conical, doserless grinders such as Baratza’s Virtuoso Preciso or Vario models allow the user to adjust the grind for all brewing devices with a macro-adjustment lever, and then fine tune for espresso with an extra set of micro-adjustments. These let the user fine-tune shots from day to day as the beans off-gas from roast and as humidity in the kitchen fluctuates. Surprisingly enough, this can have a big impact on your espresso pull. Of course, this adaptability is evident in the price, but the investment will pay off handsomely in both the quality of your coffee and in your peace of mind.

A grinder’s physical make is also an important element to take into consideration. Metal components generally need to be maintained less often and provide a sturdier build than plastic. In addition, ceramic burrs, do not dull, grind cooler than steel and have increasingly becoming a more affordable option for home use. The Baratza Vario, for example, now offers burrs manufactured by Mahlkonig to a high standard of professional quality and durability. Conical ceramic burrs can even be found in the compact and lightweight Hario Skerton Hand Coffee Mill!

One final point: When in doubt, come visit our showroom or give us a call. Our goal at Clive is to match you with the equipment that will best achieve your goals at home. Whether you wish to perfect your espresso or conquer the timeless art of the pour-over, we’re here to help you every step along the way.

Our own barista Chris Ryan tackles the topic of home grinders in Fresh Cup Magazine, a respected coffee industry publication. Scroll to page 50. From the hand grinders like the Camano to the staff favorite Baratza Vario, Chris talks through the questions to ask when considering a grinder. Got a question? Send him a note: chris@clivecoffee.com.

]]> http://www.clivecoffee.com/learn/2012/02/home-coffee-grinders-clive-in-fresh-cup-magazine/feed/ 0 http://www.clivecoffee.com/learn/2012/02/home-coffee-grinders-clive-in-fresh-cup-magazine/ http://feedproxy.google.com/~r/CliveCoffee/~3/pGYIRpDagIc/ http://www.clivecoffee.com/learn/2012/01/first-look-bonavita-versus-technivorm/#comments Tue, 10 Jan 2012 21:14:28 +0000 Mark http://www.clivecoffee.com/learn/?p=1168

For a long time, we’ve only sold the Technivorm brewer. It was the only high quality brewer we could find that was simple, reliable, and brewed at 200 degrees for 5-6 minutes, two important factors for delicious, flavorful (and not bitter) coffee.

The US market now has access to a European competitor of the Technivorm, called the Bonavita. It is available in both glass and thermal models.

As you would expect, a lot of people are comparing the two brands and asking our opinion of which model to purchase. The Bonavita and the Technivorm have similar claims to brewing time and temperature, so we did a side by side test of each brewer, and here is our opinion of the pros and cons of each:

Price: The most glaring difference between the two brands is the price. The Technivorm is $299 for the thermal models and $279 for hot plate models. The Bonavita is $159 for thermal, $129 for hot plate. I  will explain some of the reasons for this disparity in the following points. Advantage: Bonavita

Build quality: Hands down, the Technivorm is superior. From the thickness of the machined aluminum to the copper heating element, the Technivorm shows why it costs $299. It’s rugged, simple, and reliable. The Bonavita feels well built, but has the look and feel of a more conventional appliance. There’s no accounting for taste, but in our opinion the Technivorm is more attractive and feels more solid. Advantage: Technivorm.

Carafe: The Bonavita carafe is better than the Technivorm for three reasons: It’s lined with glass, so it doesn’t impart any off flavors which some people can detect from stainless; it keeps the coffee hot longer than the Technivorm carafe; and it has a pouring spout that needs no instruction. The Technivorm carafe has a distinctive mid-century inspired look, but the Bonavita held the coffee about 10° hotter than the Technivorm, both at initial brewing and after 1 hour and 4 hours. Advantage: Bonavita.

Showerhead: The Bonavita carafe has a well designed set of holes that evenly saturate the grounds, plus vents that allow the steam to escape (thus preventing condensation from dropping back into the bed). The Technivorm filter basket is an open design with a filter basket that can be easily set to no drip, fast drip, or slow drip, plus a metal spray head that can be rotated from side to side. If you want to “set it and go”, the Bonavita will saturate the bed of coffee more evenly without interference. If you want to see the bloom of fresh coffee as the hot water hits the coffee and have the option of stirring the coffee or rotating the filter basket for even extraction, the Technivorm will suit you better. Advantage: Bonavita for saturating the grounds completely, Advantage: Technivorm for analog, visible brewing.

Warranty: 5 years for Technivorm, 2 for Bonavita. Advantage: Technivorm.

Country of Origin: Technivorm is hand assembled in the Netherlands; Bonavita is made in China of German components. For some people, this will mean advantage: Technivorm. I love my iPhone which is made in China, so to me it’s not necessarily an indication of poor quality.

Brewing parameters: We did a side by side comparison of each brewer, using the same coffee and brewing parameters of 65 grams of coffee, 1.25 liters/42 oz of filtered water.

The results:

The brewing temperature and time figures are so close that we are confident saying the Bonavita heating element is about as powerful as the Technivorm. The 1,000 watt rating is a big factor here. As mentioned, the Bonavita carafe holds the temperature better than the Technivorm carafe. I should mention that the initial coffee temperatures of 185° for the Bonavita and 174° for the Technivorm are PLENTY hot for most people. I have to let the coffee rest and cool to about 165° before I can drink it.

Blind taste test: As always our goal when testing new products is two fold. We want to find out what the unit is capable using best practices AND how the typical person will use it (i.e., without too much futzing with brewing parameters). We tested coffees from several roasters and used all sorts of filters, such as the Melitta unbleached filters that came with the Bonavita (a clue to its heritage), Technivorm/Filtropa filters, gold tone filters, and Swiss Gold filters. We tried it with pre-rinsed paper filters and unrinsed filters.

And?????

Not too surprisingly, the cup quality (“taste”) depended mostly on using the best paper filter (a bleached pre-rinsed filter) and dialing in the correct grind setting (we found the Bonavita prefers a slightly coarser grind than the Technivorm). When we brewed the Technivorm with our recommended parameters (watch the video here), some of our testers preferred it to the Bonavita. When we left the Technivorm alone and did not agitate the bed at all to ensure even extraction, we got a few batches with some unsaturated grounds, and thus the Bonavita won.

At the end of the day, the Technivorm and the Bonavita both offer flavorful, hot coffee out of a drip brewer, but with different value propositions. If you like car analogies, the Technivorm is a rugged, safe, well built Volvo station wagon. It will last almost forever, and it bears a certain aesthetic heritage. It’s distinctively Netherlandic if that’s the word I’m looking for.

The Bonavita is perhaps analogous to a Toyota Camry. It’s simple, reliable, and affordable. It’s purpose is not to win design awards, but to offer great coffee and a quality appliance at a fantastic price.

It’s up to you to decide which one is a better fit for your lifestyle. See the full Bonavita lineup, or check out the Technivorm options.

*NOTE: We will be doing more testing over the coming weeks with logged data points and will gladly share our results upon request. We are also working on a video of both brewers in action. Stay tuned!

Ellanie and Ethan give it a go in the Clive Coffee showroom, using the Izzo Duetto.

If they can, you can too.