8 ESPRESSO AT HOME
BREWING APPARATUS
Sooner or later those who enjoy espresso at caffès and bars begin to think about making their own espresso drinks at home. For many the prospect may appear intimidating. The caffè machines hiss, produce alarming noises, and are large, complex, and obviously expensive.
Home espresso brewing, although more complex than many culinary procedures, is not difficult in the long run. It does require some patience, however, both in the selection of gear and in mastering various procedures. And, as with most undertakings dependent on technology, the more you spend on equipment, the less detail you need to master. Nevertheless, even those prepared to spend large sums of money on the best equipment need to master some procedure, plus understand the principles behind that procedure. Espresso is still an undertaking in which excellence needs to be learned, rather than simply bought.
This chapter and the related Espresso Break on brewing equipment (here) offer an orientation to various classes of home espresso brewing equipment and some advice on choosing that equipment. If you already own a satisfactory espresso apparatus, skip to Chapter 9 and related Espresso Breaks for some advice and encouragement on using that apparatus.
DECIDING WHAT YOU WANT
The first step in buying an espresso brewing system is deciding what you like about espresso, and how much you are willing to spend to get it at home.
For example, if you simply like the bittersweet tang of dark-roasted coffee, and can do without the rich, heavy body of espresso-style coffee, you can get by very cheaply. All you need do is buy some dark-roasted coffee and make it in your drip brewer as you would with any other coffee. And, if you want to top it with frothed milk, you can buy a little $20 device that permits you to froth milk by pumping a plunger through it for twenty or thirty seconds (see here).
If you do like espresso, but only mixed with lots of hot, frothed milk, you do need specialized equipment, but by espresso standards it can be relatively inexpensive. The under-$100 brewing devices in category 2, here, used with the $20 blade grinder, and used knowledgeably, will produce satisfying milk-heavy drinks like caffè lattes. Such relatively inexpensive brewers will not produce a satisfying demitasse of straight espresso, however. For straight espresso and espresso-heavy drinks you need something resembling the larger household machines described in categories 3 and 4 here. You also need precision-ground coffee, produced either by a specialized home espresso grinder (see Chapter 7) or in the form of little one-serving bags called pods (see here).
For those who are deeply attracted to the romance and mystique of espresso, or who entertain often and on a large scale, or who are contemplating outfitting a small office with espresso capability, a complete high-end system is a necessity, including specialized grinder with doser and a heavy-duty, refillable pump machine with cup warmer (high end of category 3, here). A fully automatic machine (also high end of category 3) is another attractive possibility for those outfitting small offices or who entertain heavily.
Once you have an idea of what your goal is, you might familiarize yourself with the various categories of brewing equipment described here, then return to this chapter to glance over the discussion that follows on various points of comparison among competing designs within each category.
POINTS OF COMPARISON FOR CATEGORY 1 BREWERS
These little devices, described and illustrated here, produce a rather thin-bodied beverage closer to strong drip or French-press coffee than to true espresso. Nor do they offer milk-frothing capacity.
“Moka”-Style Category 1 Designs. The clearest point of comparison among the hourglass-shaped “Moka”-style pots illustrated here is the material used in the top part of the pot, which receives the freshly brewed coffee as it sputters up through the filter. The best of these designs use ceramic or glass for this part of the pot; the next best use stainless steel; the worst use aluminum. Aluminum, and to a lesser degree stainless steel, become so hot that the metal burns the first dribbles of brewed coffee, often spoiling the taste of the entire batch. Some versions of this design make the ceramic, coffee-receiving, top part of the device removable, so that it can be lifted off the rest of the pot and taken to the table.
The other point of comparison among the Moka-style pots is appearance. The international design community has been loosed on these devices. Designer versions of the Moka-style pot can cost up to $200, and are among the most visually elegant of coffee-making apparatus. Keep in mind, however, that regardless of looks and price, all of the Moka-style pots work the same way.
Other Category 1 Designs. Designs like the little pot illustrated here that deliver the coffee directly into the cup are a good idea. The cup is automatically prewarmed and the coffee is not burned by contact with hot metal. The style of pot illustrated at the bottom here has two additional advantages: First, the filter receptacle that holds the ground coffee is set off to the side of the water reservoir, which means more heat can be applied to the water without baking the ground coffee; second, the caffè-style filter holder that contains the ground coffee can be removed without disassembling the pot, which makes it easier to recharge the device with ground coffee when brewing multiple servings. Used knowledgeably, devices like this one can make excellent espresso.
POINTS OF COMPARISON FOR CATEGORY 2 MACHINES
These are small countertop steam-pressure brewers with a valve and wand for frothing milk. See here for an illustrated description. Heat is provided by a built-in electric element and the coffee is held in a removable, caffè-style filter holder that clamps into the front of the brewer. The main points of comparison among these popular, widely distributed devices:
Coffee control. The best of these devices incorporate a switch or other means to cut off the flow of coffee. I would not purchase a brewer without this function, which is essential, both as a means for timing the brewing operation to prevent overextracted coffee, and as a way of diverting all of the accumulated pressure in the boiler to the milk-frothing operation once the brewing procedure is finished.
Steam control. The best of these devices have an adjustable, screw-type steam valve, which permits you to modulate the strength of the steam flow for fine-tuned control of the milk-frothing and heating operation. Some designs control the steam function with a simple on-off switch.
Special milk-frothing nozzles. Some designs seek to assist the novice milk-frother by adding various special nozzles to the end of the steam wand. All of these gadgets are essentially aerating devices that introduce room-temperature air into the coffee along with the steam. The radical designs that literally suck cold milk out of a carton and spew it out frothed into a cup are only available with some category 3 pump machines. The simpler aerating nozzles available on the machines in this category are a mixed blessing. Although they assist in the milk-frothing operation, they complicate clean-up. See the Espresso Break on milk-frothing, here.
POINTS OF COMPARISON FOR CATEGORY 3 MACHINES
These devices, illustrated and described here, are genuine espresso “machines.” Used properly they will produce an authentic tazzina of espresso: rich, sweet, almost syrupy in weight, and topped with a dense-textured head of golden crema. They all use a pump to drive the brewing water through the tightly packed coffee; they all provide milk-frothing apparatus; they all use a detachable, caffè-style filter and filter holder, except for those machines that are entirely (or almost entirely) automatic and do everything at the touch of a button, including grinding, loading, and tamping the coffee.
The many machines in this category offer a very wide range of features, comparison points, and prices. They can be loosely divided into three subcategories: lighter-weight, smaller machines that at this writing sell for under $200; heavier, larger machines that sell for about $250 to $500; and completely automatic machines that retail for $650 to $1,000. I will add a few words at the end of this section on fully or almost fully automatic machines. The points of comparison outlined below apply to distinctions among the many conventional, semi-automatic pump machines.
Category 3: General Points of Comparison
Materials and weight together constitute one of the main points that distinguish higher- from lower-priced designs in category 3 machines. Weight is not simply a psychological factor; the heavier the machine the less likely it is to slide away when you clamp the filter holder into the group. Italians call such lightweight machines macchine ballante, “dancing machines.”
In the higher-priced machines the boiler is usually constructed of brass (unless the heating is accomplished by a coil in what usually is called a thermal block unit); in the lower-priced machines the boiler is usually made of aluminum. In the higher-priced machines the group and filter holder are heavy, and fit together authoritatively; in less expensive machines both may be a bit on the flimsy, dancing side. In the finest machines the housing is made of metal; in lower-to-medium-priced machines, it is constructed of varying weights of plastic.
I strongly recommend that you commit an extra hundred dollars or so to buying at the sturdy, heavy end of the price–quality continuum. Some of the under $200 machines I have tested have proved to be very short-lived.
The complexity and convenience of the transition between brewing and frothing functions also may be a point of comparison for pump machines. Some require the operator to hold down a button for up to thirty seconds; others require only pressing a switch, and accomplish the transition in half that time.
The water reservoir is removable in most machines, which simplifies refilling. A few of the smaller machines may have built-in reservoirs, a minor inconvenience.
Most machines provide a means for keeping the filter inside the filter holder when you knock out the spent grounds in preparation for charging the filter with another dose of ground coffee. This is a small but important feature. A few machines may not have it at all; others may incorporate a little thumb flap that needs to be held down manually as you knock out the coffee. The best filter catches utilize magnets, spring clips, or sliding tabs. The filter remains securely in place while you are brewing, but pops out easily for cleaning or for switching to another filter with larger or smaller capacity.
External design aspects vary. Some machines have a deep, removable drip tray, which accommodates a good deal of waste liquid and can be lifted out of the machine for dumping and cleaning. Other machines have a smallish drip tray that requires either unplugging the machine and carrying it to the sink or sopping up the waste liquid with repeated passes of a sponge. The steam wand of some machines is awkwardly placed, with the nozzle too close to counter or drip tray to permit easy access for a milk-frothing pitcher. This design failure can be particularly irritating for North Americans who take their espresso with large quantities of milk, and who may find themselves indulging in odd kitchen acrobatics to extract full milk pitchers out from under strangely positioned steam wands.
Category 3: Special Features
A rather bewildering variety of special features also distinguishes category 3 machines, although many constitute minor enhancements or conveniences rather than major points of comparison.
Milk-Frothing Enhancements. Various devices that fit on the steam wand to make frothing easier are described here. A few machines come equipped with a little plastic can-shaped turbine device that sucks cold milk out of a carton or container, froths and heats it, and spews the hot froth into a pitcher or cup. These devices produce a very nicely textured, dense froth, but need to be taken apart and cleaned obsessively to prevent build-up of milk residues and are rather delicate, misfunctioning easily. In short, they are reassuring in concept, but annoying in practice. With some home machines, the Faema line for example, the little automatic frother (Faema calls it “Cappuccino Magic”) can be removed and replaced with a conventional steam wand, which makes sense. However, I would strongly recommend against buying a machine that only gives you the option of an automatic frother.
Crema-Enhancing Options. Some machines also provide special filter holders that improve production of crema, the pale gold froth that covers the surface of a well-made tazzina of straight espresso. For those who prefer their espresso straight, without frothed milk, these crema-enhancing devices may be an important feature. All of the category 3 machines, used properly with fresh, precision-ground coffee, will produce some crema, but these special filter holders ensure success. For more on the crema issue, see the Espresso Break.
Grind-Compensating Filter Holder. At least one currently available line of machines, the Starbucks Barista series, incorporates a filter holder that permits the user to compensate for a less-than-precise grind by moving the handle of the filter holder to the right or left, slowing down or speeding up the flow of coffee through the grounds. This is a useful feature.
Water Softeners. Calcium build-up from hard water can disable small home pump machines by clogging the pump and other components. A few machines incorporate built-in water-softening devices, which eliminate the need to decalcify the machine on a regular basis or brew with distilled water.
Cup Warmers. Some machines also come with cup warmers, which are useful, particularly for straight espresso drinkers. The little cups used for espresso must be prewarmed or they will cool the coffee and shrink the head of crema. Caffè latte and cappuccino drinkers have less to be concerned about in this regard, since the hot frothed milk partly compensates for the cooling impact of glass or cup.
Antidrip Mechanisms. The group and steam wand of some pump machines have an annoying tendency to leak slightly when the power is on. Some machines incorporate antidrip mechanisms intended to alleviate this minor incontinence.
Other Amenities. Finally, there are various amenities like accessory drawers, built-in tampers, and knock-out drawers for spent grounds. Tampers are the little disk-shaped devices used to press the ground coffee into the filter. Tampers protruding from the side of lightweight machines are frustrating because both tamper and machine tend to jitter away when you try to put a firm tamp on a dose of coffee. I prefer handheld tampers. Built-in knock-out drawers for spent grounds would be useful if they weren’t usually too flimsy to take a good knock.
The Pod Option. In the world of espresso, pods are neither alien egg sacs nor spaceship components, but rather pre-packed, one-serving pouches of pre-ground espresso coffee. Some manufacturers may call their pods capsules or other alternative space-age names. Whatever they are called, pods eliminate the most troublesome aspect of espresso brewing, which is grinding, dosing, and tamping the coffee. Unfortunately, pods are expensive, deliver somewhat less-than-fresh coffee, and require a machine that comes with special pod-compatible filters.
Pod-capable machines roughly break into two categories: those that can be used only with pods, usually proprietary format pods, and those that permit you to switch between conventional brewing and pod brewing and accept standardized, generic pods. Machines that take the standardized format pods usually carry the ESE (Easy Serving Espresso) trademark.
If you are interested in the option of using pods, I strongly recommend that you buy a machine that gives you maximum flexibility. In other words, a machine that allows you to switch between conventional load-and-tamp brewing and pod brewing using the ESE standard.
Category 3: Summary of Points of Comparison
To conclude:
• How heavy is the machine? Does it have a brass boiler and metal housing? Does it appear to be sturdy enough to stand up to the use you intend to put it?
• Is the transitional procedure for moving between brewing coffee and frothing milk more lengthy or more cumbersome than the similar procedure in other machines?
• Is there an adequate catch to hold the filter in the filter holder when spent grounds are knocked out?
• If the machine offers a gadget approach to milk frothing, is it possible to remove the gadget and froth milk in the conventional manner? Is the steam control adjustable, or does it simply turn on? (Adjustable is better.) Is the steam wand easy to access?
• Is the drip tray shallow and fixed, or deep and removable? (Deep and removable is better.)
• If the machine is designed to use only pods, can it use standardized ESE-format pods, or only those proprietary-designed pods provided by the manufacturer of the machine?
• Do you find other features of the machine attractive?
• What sort of service arrangement does your seller offer? This question is particularly important in regard to more exotic or more expensive machines, which may require specialized servicing.
Of course, all of these features need to be weighed against cost. Many of us find it easy to tolerate a few missing features or awkward design solutions in a machine that costs a couple of hundred dollars less than its competitors, but is just as sturdy and fundamentally functional.
Category 3: Fully Automatic Machines
Calling these machines “fully automatic” may be misleading to a North American caffè latte drinker. What is fully automated is the grinding and brewing procedure. You still need to froth the milk and combine it with the coffee to produce drinks like caffè latte and cappuccino.
These automatic devices start with a standard pump machine and build into it a coffee-grinding unit similar to the specialized home espresso grinders described in Chapter 7, together with a mechanism that, at the touch of a button, does all of the fussy little things necessary to producing good espresso. It grinds the coffee, packs it into the filter, starts and stops the brewing, and dumps the spent grounds.
At this writing only three lines of fully automatic machines are imported into North America for home (as opposed to office or restaurant) use. A handsome Capresso model sells for around $900 and the Gaggia Automatica for $1,200. The well-established Saeco line ranges in price from $650 to $1,000. All Saeco automatic models use the same sturdy, serviceable brewing mechanism, but higher-priced models add more power, permitting you to brew coffee and froth milk at the same time rather than switching between the two functions. Higher-priced models also incorporate a second reservoir for pre-ground coffee, which allows switching between a whole-bean coffee in one reservoir and a second, pre-ground coffee (decaffeinated, for example) in the second. This last feature is useful when entertaining, since you can switch between regular and decaffeinated coffee at the touch of a button. Finally, higher-priced models have more sophisticated digital controls.
POINTS OF COMPARISON FOR CATEGORY 4 MACHINES
Those who choose one of these romantically old-fashioned devices (see here for a description and illustration) love their appearance and charming directness and value their solidity.
At this writing machines in this category retail for about $450 to $800, depending on the following points of comparison:
Boiler Capacity. Since these devices need to be cooled down before being refilled, and once refilled take ten minutes or more to achieve brewing temperature, a large capacity boiler is a distinct advantage for those who entertain.
Pressure/Temperature Control and Pressure Gauge. Most machines in this category incorporate a pressure-sensitive temperature control that adjusts heat in the boiler to maintain relatively even steam pressure in the boiler. This feature permits you to leave the machine turned on for prolonged periods, sparing you a long wait for it to heat up, and probably saving on energy costs as well. More expensive machines also incorporate a pressure gauge, a wonderfully retro, industrial revolution–style dial that give you a reading of steam pressure. This last feature is not essential, but it is both picturesque and reassuring. The more we know about steam pressure the better.
Piston Mechanism. At this writing two machines in this category, the Riviera Bristol and the Electra, offer a true spring-loaded piston mechanism, whereas others simply use the muscle power of the operator to force the brewing water through the coffee. The spring-loaded design exerts considerably more pressure on the brewing water than the muscle-only models, but demands a skillful operator and a precise grind to take advantage of that pressure. For espresso beginners I would recommend the much more forgiving manual piston designs like the widely distributed Pavoni Europiccola.
Appearance. The romantic appearance of these devices, with their pipes, valves, and levers, is one of the main reasons many people prefer them to the more reticent-looking pump machines. Manufacturers cater to this appeal by adding fancy finishes and exotic ornament to some models, including gold plate, brass eagles, etc.
STAND-ALONE MILK FROTHING DEVICES
With the popularity of caffè latte, chai, and other big-milk drinks, an array of stand-alone devices have appeared on appliance shelves that produce only frothed milk, without the espresso. You can use them to add frothed milk to your drip or French-press coffee, for example, producing what American coffee culture calls a café au lait. Or you can produce frothed milk for chai, or for moos, which are essentially flavored caffè lattes with the espresso left out.
Some milk frothers are simply stovetop steam boilers with valve and wand. You use them to heat and froth milk just as you would any of the espresso brewers in categories 2 through 4, as outlined here.
Other frothing devices take a very different approach. With the most popular design, you pour milk into a glass or metal decanter and pump a sort of perforated piston through it until it is frothed (about thirty seconds). These devices have no agreed-on name. Asking the clerk for a “pumping milk frother” will probably get you to the right shelf in the store.
These gadgets are reassuring to milk-frothing novices because all they ask is enough energy to pump a piston vigorously for thirty seconds. The froth produced is rather heavy and inert, however, satisfactory for a caffè latte but not for a classic cappuccino. Furthermore, heating the milk is a second, separate operation from frothing. The most convenient designs have no metal parts connected to the decanter; this permits you to place the decanter with the cold milk in a microwave. Designs with metal decanters require you to heat the milk on the stove or transfer it to a metal-free container for heating in the microwave. Some designs recommend that you heat the milk before frothing; others after.
I certainly wouldn’t blame a beginner for buying one of these $15 to $40 devices, but if you brew espresso and if your espresso brewer incorporates a steam wand, you will find it easier and simpler over the long haul to learn to froth milk in a conventional way.
Additional stand-alone frothing devices are appearing on coffee-store shelves, and I am sure that still more will appear after this book has gone to print. The latest is a mini battery-operated mixer, the Bon-Jour Caffè Froth Turbo. You simply stick the mixing head in (cold) milk and push a button, then track the developing froth upward with the mixing head. You still need to heat the frothed milk in the microwave, however.
ESPRESSO BREAK
FROM POT TO MACHINE
Home Espresso Apparatuses
Home brewing devices for espresso range from the modest little stovetop pots Italians call caffettiere, or “coffee pots,” that retail for as little as $15, to fully automatic devices that produce espresso virtually equal to the best caffè production at the press of a button, and cost as much as $1,000. Most home espresso brewing devices fall between these extremes of price and capability. For purposes of analysis I’ve divided them into four broad categories.
CATEGORY 1: Simple Stovetop Brewers
• Without valve for frothing and heating milk
• Without mechanism for controlling coffee output
• Brewing pressure supplied by natural build-up of steam pressure trapped in boiler
Advantages. Some designs are very inexpensive; others are very attractive.
Disadvantages. Cannot produce espresso drinks using frothed milk; require great care to produce even passable espresso; can only brew multiple servings.
These little devices are not true espresso brewers. Unless used with the greatest care they produce a thin, bitter, overextracted coffee that only an Italian could love, and not for very long if there is an espresso bar around.
The most familiar profile is the hourglass design shown here and called a Moka-style pot, after the model name for the most famous and widely distributed of the brewers using this design. The illustration provides a cutaway view of such a device. The water boils in the bottom part of the pot (A); the pressure of the trapped steam forces hot water up a tube and through the ground coffee held in a metal filter at the waist of the pot (B). The brewed coffee trickles out into the receptacle at the top of the pot (C).
Moka-style pot
Stovetop pot brewing directly into cup
Stovetop pot incorporating caffè-style filter holder
All of the various designs illustrated here, as well as those described in later pages as category 2, work in similar fashion, using the pressure of trapped steam to force the brewing water through the coffee. All provide a brewing pressure of about 1½ to 3 atmospheres, considerably less than the 9 or more atmospheres now considered optimum for espresso brewing.
Designs like the example illustrated at the left brew the coffee directly into the cup, and designs like the devices on the bottom left brew into a separate receptacle and make use of an external, caffè-style filter holder and filter.
CATEGORY 2: Countertop Steam Pressure Brewers
• With valve for frothing and heating milk
• With mechanism for controlling coffee output
• Brewing pressure supplied by natural build-up of steam pressure trapped in boiler
Advantages. Relatively inexpensive; provide more predictable, stable steam pressure than stovetop models in category 1. Operated carefully can produce acceptable espresso drinks with frothed milk; can be used to froth milk or prepare hot beverages independent of the coffee-making operation.
Disadvantages. Cannot produce authentic straight espresso; require care to produce espresso acceptable for frothed milk drinks; occupy some counter space.
Devices of this design are currently the most popular of espresso brewers on the North American market. Like the category 1 stovetop devices they brew coffee using the pressure of trapped steam, but they add an electric heating element, which promotes a more consistent and safer steam pressure, and a valve and wand for frothing and heating milk. See the cross-section illustration on the bottom right. The closed boiler (A) generates steam, which forces the hot water below it out and through the ground coffee in the filter and filter holder at (B). The steam wand (C) controlled by a steam valve (D) taps the steam for milk frothing.
These brewers are designed to provide the North American “latte” and casual cappuccino drinker with an adequate drink at a reasonable price. They retail between $50 and $100. All provide a steam valve and wand for frothing and heating milk. All have an aluminum boiler or water reservoir with stainless steel filter and filter holder. All separate the filter and filter holder from the boiler to avoid overheating the ground coffee, and all have a removable, caffè-style filter and filter holder.
CATEGORY 3: Countertop Pump Machines
• With valve for frothing and heating milk
• Switch-activated pump system controls coffee output
• Brewing pressure supplied by pump. Approximate pressure 6 to 15 atmospheres
Advantages. Make near caffè-quality espresso and espresso drinks with frothed milk if used correctly; refillable reservoirs make it possible to produce any number of espresso drinks without interruption or cool-down; achieve brewing temperature relatively rapidly; brew with water held at optimum (lower-than-boiling) brewing temperature.
Countertop steam pressure brewer
Cross-section, countertop steam pressure brewer
Typical home pump machine
Cross-section, home pump machine
Disadvantages. Take up counter space; more expensive than category 2 devices; more reticent and less romantic in appearance and operation than category 4 machines; in many cases less sturdy than category 4 machines. The cheapest of these devices (under $200 at this writing) are often flimsy, and should be avoided in favor of sturdier, heavier models that (regrettably) cost a bit more.
At this point we enter the world of the true home espresso machine. All of the devices in this and the following category 4 provide means to press the hot water through the coffee bed at pressures considerably exceeding the approximately 1½ atmospheres generated by steam pressure alone. All provide steam valves and wands; all utilize separate caffè-style filters and filter holders that can be repeatedly charged with ground coffee for multiple “pulls” of one or two servings of espresso each.
The designs in this category provide additional pressure on the hot water by means of an electric pump; a separate function provides steam for milk-frothing. The separation of brewing and frothing functions permits the brewing water to be delivered to the coffee at the 186–192°F authorities agree is optimum for espresso brewing. Machines in other categories do not control the temperature of the brewing water as precisely as machines in this category.
In almost all pump machines the operator is asked to first brew the coffee, then activate a switch or hold down a button, which raises the heat in the boiler or heating coil from the lower brewing temperature to a higher temperature appropriate for steam production.
Internal Elements. The principal concealed elements of pump machines are indicated in the simplified diagram on the previous page: a water reservoir (A), in which the water is held at room temperature and which can be refilled while the machine is in use; a pump (B) for transferring water from reservoir to boiler and for pressing the brewing water through the coffee; a small boiler (C) for heating water for brewing and steam production; and various control mechanisms, including two thermostats, one for controlling the heat applied to the water during brewing, and one for controlling the considerably higher heat applied to the water during the production of steam for milk-frothing.
External Elements. The external features mimic the features of the large caffè machines. They include: (D) an opening for servicing the water reservoir; (E) a gauge to indicate water level in the reservoir; (F) the brewing group, into which the filter holder clamps; (G) the filter holder and filter basket; (H) the steam wand or pipe; (I) the steam nozzle used to froth milk; (K) the controls, usually including a power switch and switches that activate the brewing and steam functions; and (L) the drip tray. Some designs, like the one pictured, also may include a cup-warming shelf atop the machine (M) and a built-in tamper (N).
Fully Automatic Machines. Some home pump machines brew coffee automatically, at the touch of a button. See here for an illustration of such a machine. A series of mechanisms inside the machine grind the coffee, load it, tamp it, press the appropriate volume of water through the ground coffee, and finally drop the spent grounds into a removable waste container, all at the touch of a button. For drinks with frothed milk the operator still must froth the milk and assemble the drink, however.
Pod-Capable and Pod-Only Machines. In an effort to simplify the espresso brewing process manufacturers have developed home machines that give users the option of using small teabag-like individual servings of pre-ground coffee called pods. The most radical of these machines use special proprietary pods, which means you must buy your coffee for the life of your machine from the same people who manufactured it. Other, ESE-standard, machines use any pod that follows the widely adopted ESE standard, obviously an advantage in terms of price and range of choice. The ESE machines also typically offer the option of using either pods or conventional brewing procedure.
Typical home piston machine
CATEGORY 4 Countertop Piston Machines
• With valve for frothing and heating milk
• Hand-operated piston controls coffee output
• Brewing pressure supplied by spring-loaded or hand-operated piston. Brewing pressure supplied by the piston will vary, but will considerably exceed the pressure supplied by trapped steam in the category 1 and 2 devices
Advantages. Make near caffè-quality espresso and espresso drinks with frothed milk if used correctly; sturdier in construction than all but the most expensive category 3 machines; more conversation-provoking in appearance and operation than category 3 machines; offer more finely tuned control of brewing pressure than category 3 machines.
Disadvantages. Take up counter space; expensive; slower to warm up than category 3 machines; must be turned off and bled of steam pressure before refilling; boiler is exposed in most machines, and hot to the touch; manual piston designs may not provide as strong a brewing pressure as category 3 machines.
The sometimes hard-to-find machines in this category are piston devices, in which the additional pressure applied to the brewing water is delivered by a piston fitted into a cylinder, much as it is in the large piston machines still in use in many North American caffès. The piston is lifted, drawing water into the cylinder under the piston and above the bed of ground coffee, then depressed, pressing the water down through the coffee.
At least two currently available machines in this category incorporate a spring-loaded piston similar in design to the large manual caffè machines. A lever is depressed, compressing a spring above the piston; the spring then presses piston and water down, while the lever handle slowly returns to its original upright position. See here for a cross-section illustration of such a mechanism.
However, most of the machines available in this category, including the widely available Pavoni Europiccola use the simple muscle power of the operator to provide the brewing pressure on the water. See the illustration on the right showing a cross-section of a typical manual piston machine. You raise the lever (A), drawing water from the boiler (B) into the cylinder (C). Next you lean on the lever, forcing the piston (D) down, and the brewing water through the filter holder and coffee at (E). Steam for milk frothing is provided by tapping the top of the boiler with the usual wand and valve (F).
Unlike the pump machines in category 3, these designs hold the water for both milk-frothing and coffee-brewing in the same large reservoir. This arrangement involves a couple of drawbacks. First, you need to wait for the entire reservoir to heat up before beginning to brew, a procedure that may take up to five minutes. Second, you must cool the entire machine before refilling the water reservoir. The pump machines in category 4 can be refilled while in use.
The great advantages to these machines are their solid construction and romantic appearance. Some aficionados also prefer to apply manual pressure to the brewing water because they can fine-tune the brewing pressure to compensate for variations in fineness of grind and the effects of humidity on the resistance of the coffee.
Home piston machines are often difficult to find. If you need help identifying a supplier, see Sources.
Cross-section, home piston machine