I've received several queries in the last month asking me about the various domestic espresso machines now appearing in major department stores. Brands mentioned have been Sunbeam, DeLonghi, Breville, Krups and recently Gaggia. The Gaggia company is now wholly owned by Saeco, as is CMS, the Australian Saeco distributor, which has become Saeco Australia P/L.

All this corporate mixing will probably mean big changes in the product lines and distribution arrangements, and the first of these are appearing. The Gaggia agency has been moved after many years at Coffee Mio and is now distributed by the former Krups agent ex Sydney, thus its appearance in the big stores.

Anyway, when I looked at the machines there were so many different models to choose from that a thorough evaluation seemed impossible. Then I realised that I didn't really need to look at specific machines so much as the way they are put together. So this article concentrates on the components rather then the brand or model.

The stock ULKA pump found in so many machines.

To begin with, the pump. 18 Bar, 15 Bar, 9 Bar...what's the difference? In reality, none. ALL the pumps used in domestic machines are vibration pumps, usually made by either Eaton or ULKA, and all of them are basically identical. As long as the machine has a pump, you can ignore the "Bar" ratings.

Then comes the heating technology, and it's here where fundamental differences which profoundly affect espresso production occur.

An aluminium thermoblock with exterior element. Inside the block. "A maze of twisty channels, all alike."

"Thermoblock" technology means that the water is heated in a multi channel metal block with an exterior element. The total volume of water inside the block at any given time is small, no more than 10ml, and the theory is that heating the block via an external element and pushing the water through at a set flow rate will produce the correct water temperature. In practice the first water touching the coffee is too hot and the rest usually too cool. In addition the flow restriction reduces the pressure at the group, making normal extraction difficult, so ALL thermoblock machines use "crema enhancing" devices of various types.

A 900w stainless steel boiler as used by Krups, Saeco etc. An inside view of a 900W stainless steel boiler

Steaming is accomplished by using the pump to pulse small bursts of water into the overheated block, which is then supposed to flash into steam. Again in practice steam production tends to be feeble and "wet".

Thermoblock machines will produce average espresso and reasonable milk drinks given good technique, but anyone who wants better than average should avoid them.

The standard S/S boiler on the left, and the Silvia boiler on the right. Big, isn't it?

Boiler machines tend to fall into 3 categories:

• Gaggia, which have a proprietary aluminium boiler with 2 external heating elements and a boiler volume of 120ml;
  
• Stainless steel with copper element, boiler volume 180ml;
  
• Marine brass with copper element, boiler volume 300ml.
  
  

All 3 boiler types have sufficient water volume to keep reasonable temperature stability throughout a double shot. When heated to steam temperature, the limited volumes of the smaller boilers can mean slightly less steam time and power, but all have enough for average use. In my experience the larger volume boilers have a faster "recovery time" between shots and that bit of extra steam, so that you can produce 6 cappuccinos in 5 minutes for your dinner party.

Again in my experience the Gaggia boilers tend to corrode internally. They are attached to a brass group, and the combination of dissimilar metals and hot electrically conductive water simply eats the aluminium. This can also happen with aluminium thermoblocks, which is why some of the more upmarket ones are now lined with stainless steel.

Inside an 18 month old Gaggia boiler. The aluminium top has corroded, the chromed brass base is in perfect condition. This close-up shows the extent to which the metal has been eaten away.

Finally, the larger brass boilers tend to have higher power elements than the smaller stainless steel ones, again giving better thermal stability and faster recovery.

The GROUP is the bit of the machine that the portafilter locks in to, where the water is pumped through a "showerscreen" on to the coffee. All of the thermoblock machines I've seen have aluminium groups with stainless steel shower screens. The smaller stainless steel boiler machines also have aluminium exterior groups and S/S screens. Gaggias have a brass group with a S/S screen, brass boiler machines have brass groups with S/S screens. Of all domestic machines, only the Rancilio Silvia has a commercial brass group and S/S screen setup.

The "Commercial" group as found on the Rancilio Silvia. The "Commercial" Rancilio 58mm portafilter is on the right, the 57mm Quaha is on the left.

Portafilters are another point of differentiation, with (again) thermoblock machines tending to have cheap aluminium portafilters and quality boiler machines chromed brass portafilters. All this concentration on metal types may seem a bit strange, but excellent espresso production relies on thermal stability of all the components in the process. Copper and brass are best, which is why you find them in commercial machines.

Both Gaggia and Rancilio use commercial portafilters and baskets on their domestic machines. Solis and Quaha have brass portafilters but non-commercial filter baskets. Saeco uses its patented pressurized portafilter, made mostly of plastic but with some brass, as does Krups on its higher end machines. The Saeco portafilter pops up on other brands of machines such as La Pavoni and Spidem, so it's a good bet that these brands are "rebadges", Saeco inside another manufacturer's body design.

All the rest (as far as I could tell) are aluminium, lightweight and cheap.

Solenoid "3-way" valves are only available on high end machines, they relieve pressure in the portafilter immediately after brewing so you can pull consecutive shots.

Recommendations

Now we get down to the hard part, what do I recommend and why?

The Krups Vivo (Gusto) 880. A$230. Gaggia Carezza, same insides and portafilter as the "Coffee", A$330. Gaggia Classic, as for the Carezza, but S/S body and 3 way solenoid. A$599.

Well, from the cheapest to the most expensive, here they are. Krups Vivo K880, (also called the Gusto in North America) approx. A$230.00 (US$119), has a pump, stainless steel boiler, cheap portafilter but with good technique you can make a decent espresso.

Gaggia Carreza, A$330.00 (US$189), a modern Gaggia Coffee at half the original price. I can't believe that they're suddenly so cheap, but it appears Saeco is determined to establish them as a mass market brand. Simply kills ALL the thermoblock opposition anywhere near the price, as well as any other non-solenoid machine. Buy this in preference to Sunbeam, Saeco, Breville (Dualit elsewhere) DeLonghi, Krups Novo et al.

Gaggia Classic A$599.00 (US$379). $200.00 cheaper than it was a couple of months ago, commercial group, 3-way valve, S/S body.

Quaha Junior II, 100% S/S body, brass boiler, 3 way solenoid. A$495. Quaha Napoletana II, S/S body, brass boiler, 3 way solenoid and grinder, A$682 Rancilio Silvia, one with the lot! A$748.

Quaha Junior II, A$495.00, S/S body, 3-way valve, but non-commercial portafilter and group. Produces identical espresso to the Classic but A$100.00 cheaper and longer boiler life.

Quaha Napoletana II, A$682.00, as for the Junior but includes built in Lux (a.k.a. Isomac, Innova Conical etc.) grinder. Best "value for money" kit I know of. NOT available in the USA, so please don't ask me!

Rancilio Silvia, A$748.00 (US$395). In my opinion the only home espresso machine that can consistently produce "commercial" quality espresso or better, limited only by operator technique. S/S body, fully commercial group, water distribution and portafilter system, 3-way valve.

All I want for Christmas is... a Tea! A$2000.

The step up from the Silvia is a tall one, around A$2,000 for a Pasquini Livia, Isomac TEA or ECM Giotto. These machines are really single group commercial machines with a tank and vibratory pump setup, instead of being plumbed in with a rotary pump. Boilers are usually around a litre or more, which is a lot of water to heat up if you only make a couple of espressos a day.