Replies to This Discussion

Permalink Reply by Brady on February 10, 2010 at 8:12am

Here's the rundown:

Traditional machines require the barista to grind and dose coffee into the portafilters, and remove the spent puck after the shot has finished. There are 3 basic types, with the difference being the way water pressure is applied:
Manual or Lever machines rely on the barista to pull a lever to apply pressure (like an old well hand pump) OR activate springs to do the work. Rarely seen in the US.

Semi-auto machines use an electric pump for pressure. The pump is started and stopped by the barista (usually using a single button), so you can dispense as much or as little water as you like.

Automatic machines can be programmed to dispense a set quantity of water automatically, usually using a collection of buttons or a touchpad. There's usually the option to program different doses for ristretto and normal single and doubles. There is a manual-dispense function on these though. This type could probably also be called "volumetric".

The Superauto goes one step further and performs all of the grinding, dosing, extraction, and puck-ejection steps within the machine - the user only has to push a button and remember to fill the hopper with beans.

Hope that helps.

• ▶ Reply

Permalink Reply by David Brown on February 10, 2010 at 8:14pm

I'm going to add just a little, not because I'm expert in any way, but since I've been learning some of this myself recently.

Most automatic machines CAN be used in semi-auto mode, so if you want that level of control you can still have it. But on the La Marzocco machines at least, there's some compromise in temperature stability caused by the design of the flow meter that's used for "volumetric dosing" on the automatics, so the semi-autos are a bit better in that respect. This is especially true if they're idle for a significant time. There's also more stuff to go wrong on the more complex automatic machines. But again, on La Marzocco machines, if the electronics fail you can still use them in semi-auto mode.

Seems many of the better shops prefer the control and temperature stability of the semi-auto. The semiauto forces the barista monitor the shot quality and cut off the shot manually, and many feel that the automatic allows a lack of attention that can lead to loss of quality, even though its not really inherent to the machine.

However an automatic can minimize the harm that can be done by poorly trained or overly busy baristas. The temperature issues of the automatic can reasonably be addressed with a little extra group flushing.

• ▶ Reply

Permalink Reply by Mike McGinness on February 10, 2010 at 10:36pm

This is only true of older LM AV models. In newer LM AVs the volumetric flow meter is inside the saturated group and hence extremely temp stable whether shot initiated from idle or hammered. You can also convert old LM AVs to the new "Piero" style group, but ain't cheap, about $500 per group.

David Brown said:

I'm going to add just a little, not because I'm expert in any way, but since I've been learning some of this myself recently.

Most automatic machines CAN be used in semi-auto mode, so if you want that level of control you can still have it. But on the La Marzocco machines at least, there's some compromise in temperature stability caused by the design of the flow meter that's used for "volumetric dosing" on the automatics, so the semi-autos are a bit better in that respect. This is especially true if they're idle for a significant time. There's also more stuff to go wrong on the more complex automatic machines. But again, on La Marzocco machines, if the electronics fail you can still use them in semi-auto mode.

Seems many of the better shops prefer the control and temperature stability of the semi-auto. The semiauto forces the barista monitor the shot quality and cut off the shot manually, and many feel that the automatic allows a lack of attention that can lead to loss of quality, even though its not really inherent to the machine.

However an automatic can minimize the harm that can be done by poorly trained or overly busy baristas. The temperature issues of the automatic can reasonably be addressed with a little extra group flushing.

• ▶ Reply

▶ Reply to Discussion