timo888 wrote:Interesting. Ponte Vecchio in their documents claim the machine is always ready to brew, and that was indeed my experience, but only if it had been purged with a flush after the false pressure was bled off -- before the first pull of the day. The differences in our experiences with the machine might be explained by the pressure settings we chose -- yours "around 1.0 bar" and mine between 1.1 and 1.2 (as recommended in the PV manual).

I doubt a difference of 0.1 or 0.2 bar would account for much. While the Lusso does perform its purpose admirably, we're not dealing with a high-precision instrument. Technically the owner's manual claim is true if you make only one espresso every 30 minutes; the dynamics change if shots are pulled in succession. It could explain why they regulate it to 1.5 bar from the factory, i.e., brew temperature would be about right with zero flushing.

I've had a lot of fun working with the Lusso. It has a huge margin of error and the brew temperature management routine is uncomplicated. It's small and rugged. Frothing good microfoam is a snap. Levers are frequently branded as "hard to master" and I'm guilty of repeating that mantra in the past. But now I've evaluated two levers (Gaggia Achille, Ponte Vecchio Lusso) that are significantly easier to use than popular pump espresso machines like the Rancilio Silvia and don't have its simultaneous steam/brew limitation. A friend of mine bought the Lusso on my recommendation months ago and was pulling good shots in a few days; he even poured some respectable latte art after a few weeks.

The lesson I've (re)learned from the Lusso is that simplicity of design can work.

Quotes from Bella Barista's report on the PV Lusso 1:

The Ponte Vecchio Lusso 1 runs hot, as of course the pressure of the water in the boiler is about 1.4 bar and its temperature around 126 C. The group does have a thermosyphon effect to keep it warm, but only warm enough to not cool the brew water below optimum brewing temperature. One key function of this group is to bring the temperature of the very hot boiler water down to around 92-94 C. However, the longer the water is in the group, the cooler it gets! So a 7-second wait after pulling down the lever and a correct grind for a pour at the right speed are essential factors in getting your espresso right.

The Ponte Vecchio Lusso 1 requires no flush of any kind prior to pulling all shots (except the first shot of the day). In some respects this is quite a relief and means you don't have to fill the machine as often as you might think. I had the machine on and making coffees all day and would possibly fill it once. For my bigger HX machine and the same usage I would have filled the 3 litre cold water tank 3 or more times!

So, does that observation match your own experience? Does it sound like a good argument for keeping the factory p-stat setting?

Grazie,
Wayne

Yes and no. Greg observed and other Smackdown participants agreed that a preinfusion of 3 seconds worked best; extended preinfusion muddied the flavors.

Espresso machines like the Lusso are easily influenced by the flush regime, so one should expect there to be differing opinions about the "best" way to manage brew temperature. I will document mine with an eye on ease of use, but I'll also include sections for geeky types that want to experiment. For example, pulling back-to-back shots with 90 seconds in between. I've also perfected a routine for pulling a quad ristretto cappuccino in three minutes or less. Try that with a Silvia!

roastaroma wrote:Does it [boiler pressure setting and pre-infusion effect on heat-sink] sound like a good argument for keeping the factory p-stat setting?

I'd say it's an argument not for any specific setting -- the machine can be kept somewhere in the middle and tweaked "at runtime" in either direction, or it can be optimized in one direction (hotter) or another (cooler). It will depend on its duty cycle and the roasts you prefer.

Whether you buy from Barefoot, say, whose roasts respond well to high temperatures, or from Terroir, whose roasts respond well to relatively low temperatures, you can use a combination of p-stat setting and preinfusion time (and warming flush or no warming flush) to accommodate both fairly well, or you can optimize for one and then modify your routine as necessary to accommodate the other.

YMMV. You may want a warming flush if you set the machine at 1.0 but perhaps not if you set it at 1.2 or higher. The effects of preinfusion, whether active Fellini or passive, whether long or short, will not be independent of temperature (or dose). Experiment and enjoy. The Lusso is easy to master.

Regards
T

Finalmente, I just got my Lusso 2-group from 1st Line! Still waiting for my Thor tamper, but meanwhile I've managed to reset the p-stat to 1.1 bar. Actually the needle peaks just a hair above that, then drops to 1.05, when the boiler clicks on again. Fascinating -- much narrower deadband than my Sirena's thermostat!

Now the mad scientist in me starts to wonder: if boiler temperature correlates to pressure, then would bleeding off pressure via the steam wand cause an instant drop in boiler water temp as well? I know the drop wouldn't last long because of the p-stat, nor would it have the same effect as flushing the group head, but can a pressure drop via steam have a small, predictable effect that can be used for pulling shots when seeking a particular brew temp window? (Part of my curiosity is that I'd rather not deplete the boiler water by flushing unnecessarily.)

Happy Brewing,
Wayne

No, once the water is 230 degrees, it can't drop fast (high specific heat). The best way to brew cooler shots is keep the group cool and the pstat turned down.

I've been pulling some good-tasting shots with my Caravel with the kettle set to 197 degrees F. I'm fixin to turn down the Pstat on my PV Export soon to see how it does.

PC