aasemkhan wrote:I was recently introduced to the joys of home made espresso and have just purchased a used La Pavoni brass model (Two switch). I LOVE this machine. I may not have reached espresso Zen yet, but I'm pulling respectable shots with it.

I saw this quote at the top of a thread on polishing copper and brass on a vintage dual switch La Pavoni Europiccola. Since it's off topic, I thought I'd post these tips in a separate thread and link to it. I've been in the Zen zone (the alliteration was too tempting) recently with my dual switch Pavoni. To get there I equipped it with a group thermometer and inserted an Elektra double basket, which takes a higher dose than the stock Pavoni one. On my machine I had to chop the portafilter to fit that basket but some pre-Millennium portafilters will accommodate that basket internally. I've also added a pressure gauge on top of the sightglass. These are available at Orphan Espresso. This yields completely observable boiler pressure and group temperature. I've also added a Teflon gasket between the group and the boiler to slow temperature transfer. I've dialed in a Mazzer Super Jolly so that I dose about 16.5 to 17 gm with a fine grind that I tamp only to level. The Pavoni double basket will take a slightly smaller dose but should work fine.

Here is how to do this for a single shot. I've added instructions below for temperature controlling multiple shots. I turn on both switches and when the overpressure valve starts to vent I switch on the thermometer and then watch the temperature rise on the group. I also do a brief flush to heat the group. I do some half pumps to allow steam into the top of the group. As I approach target temperature I lock in the portafilter. The half pumps don't raise the lever high enough to pre-infuse the coffee. When it gets within 2 or 3 degrees F to the target starting temperature I toggle off both switches. Without a Teflon gasket you may need to give it a little more leeway, maybe toggling off 5 degrees before target. I do one or more half pumps to get to a predetermined temperature. I then raise the lever all the way and it stays put by itself while it pre-infuses. When drops hit the cup and start to slow, this means the grounds are expanding as they absorb water. Then I do about a 20 second pull that feels like cutting through frozen butter. I don't raise the lever and pull through again. This consistently yields rich shots that taste like they were pulled on a La Marzocco machine in a fine cafe. With very bright, light roasted beans I start the pull with the group temperature reading (outside back of the bell) as high as 198F. With a darker roast but not one into second crack I may start at 193F. Coffees like Stumptown Hairbender like lower temp like that. Coffees roasted into second crack will require a much lower start temperature* to tame the bitterness. The thermometer's the most important part of this routine. The thermometer I used costs $10. The shots are completely consistent because temperature is controlled. Here are two reference links:

Adding Thermometry to a La Pavoni Europiccola

Creating Teflon Gasket for Pre-Millennium La Pavoni

Converting the Portafilter to Bottomless
I'm pulling a shot at a time and haven't recently tried pulling back-to-back shots with this machine but expect that doing so will require varying when I toggle off before reaching target temperature on a machine that's heated up. Steaming milk with the High switch on will also raise group temperature and require cooling time, but these shots are so good I'm not using milk.

* Added: Such coffees do better with the internal 175F temperature Alan Adler recommends people use with the AeroPress. I would try targeting about 170F on the outside of the group bell for these. If it still has a bitter edge, try a little cooler. Robert Pavlis, who posts below, suggests in another thread that if you have a Robusta or a dark roast you can layer it on top of a lighter roast to filter out the harsher components while benefiting from other rich flavors these may confer.

Your call, Aasem. Refilling is no big deal. Shut off the power, bleed the pressure through the steam wand. When the pressure's all gone carefully remove the cap. Refill with warm water so as not to shock the element. Recap and power back up. I was wanting a 16 cup Professional for awhile and then was happy with the Pavonis I've got.

Of course if a Europiccola boiler isn't big enough to keep your friends entertained, why stop at a Professional? There's this six group Brugnetti Aurora sitting in the warehouse at Mr. Espresso in Oakland. It's a historic machine that was in service at the cafe where they first coined the name for the American drink called a "latte."

The Om Zone: The Zen of Back-to-Back Shots and Steaming

Begin by getting your back straight, chin slightly tucked, and settle comfortably onto your cushion. Cleanse the channels with a few alternate nostril breaths. As peaceful alertness settles in you're ready to learn the yoga of internal heat (Tummo) for the ancient peacock.

The method I now share with you was developed by Doug Jamieson, aka Fullsack, which he briefly documented here for the diligent student after demonstrating temperature stability for over two hours on his vintage La Pavoni.

Fullsack wrote:Using your palate as your guide, determine the ideal bar reading for your coffee. In the case of Barefoot's Element it was a cool .5 bar. Warm the machine to the desired bar setting, (if you get to 1.0 bar, with steam pouring from the safety valve, you overheated), start pulling the shot, but turn off the machine during pre-infusion and finish pulling the shot. When you are almost ready to pull the following shot, turn on the machine and repeat the process.

I tried that today with four shots in a row on my two-switch Pavoni, and it works. With a group thermometer there's increased precision. (If the starting pressure is at the lower end, say 0.5 or 0.6 bar, you may need to do a few pumps to lift water into the coffee cake. Drips at the bottom of the cup and pressure against the lever will tell you the coffee's been infused.) I then made the ultimate test, powering up both switches to steam pressure to make a cappuccino. Doing this raised the group temperature about 15 degrees F past the desired starting temperature for my coffee, all the up way to 210. Keep in mind that since my group is equipped with a Teflon group to boiler gasket your group may heat more. Perhaps others can contribute their results without that gasket. The good news is after waiting two minutes I chilled the bottomless portafilter under the kitchen tap, locked it in and this quickly brought the group back to a target temperature of 195F. With boiler pressure at target one can then pull another shot. Venting steam through the wand and locking in a cold bottomless portafilter gets you back to target in less than five minutes, where the boiler pressure/temperature and group temperature were back in equilibrium.

As Doug reminds us:

Fullsack wrote:When the machine needs a refill, wait until the pressure gauge is at 0 then slowly and carefully remove the cap and add water.

Controlling a dual switch La Pavoni for back-to-back shots is the Om Zone!

No, in this case it's art. Ray brought his machine to my house awhile back and it was fun to see how he'd transformed it.

La Pavoni + PID = better temperature control?