The machine I use at our main home is a Breville Dual Boiler as my main machine, which has basically all the goodies to make espresso without ministrations to compensate for inadequacy. But life circumstances has us out at the family lake house almost weekly, even if for only a day at a time. As "luck" would have it, our lake neighbor gave us a solid but simple SBDU machine, a Saeco which is basically the old Starbucks Barista machine without the *$$ labelling.

To the question: This machine has no OPV, and I can only assume the pucks are getting the full 15 bar output of the Ulka vibe pump if I use the Saeco naked portafilter I have for it. I also have a pressurized portafilter for it, but I can nary force myself to use it unless someone convinces me I ought to, because of the hugely overpressured extracting otherwise. Excluding the pressurized portafilter, I have tried a couple of things and I am curious as to your thoughts on the first versus the second:

1) Super fine grind:
I _can_ grind fine enough to choke the machine and thus I can dial it back a little to get about a 25s extraction time to reach my targeted weight. At this level, the grinds are pretty clumpy and I give them a good fluffing WDT, whipping them up with my trusty wood handled, dissecting needle. This is a much finer grind to get 25s at 15 bar than it would be to get 25s at 8-9 bar.

or

2) Cycling power to the pump:
I can grind a little coarser, to a point that would give a 25s extraction at 8-9 bar, but would be a good deal faster than 25s at 15-17 bar. When I do this, I turn off the pump a couple of times to slow the flow, so I arrive at my targeted weight in about about 25s. I worry that multiple applications of 15-17 bar might hammer the puck apart. BUT, observation of the naked extraction does not reveal any gross chanelling.

So, as far as you can tell, theoretically, am I better off with option 1 or option 2?

Or am I best off just using the pressurized portafilter?

Also, I am interested in adding an OPV. And I am not worried about packaging inside the machine. I could tape or rivet it to the outside of the machine and that would be fine with me. The biggest obstacle to me would be finding the right sized one.

-Peter

pcrussell50 wrote:This machine has no OPV, and I can only assume the pucks are getting the full 15 bar output of the Ulka vibe pump...

At zero flow, that is true, but at double espresso flow rates, the actual brew pressure is closer to 9 or 10 bar. See I still don't get it: Why adjust the OPV? for a longer explanation.

pcrussell50 wrote:So, as far as you can tell, theoretically, am I better off with option 1 or option 2?

I would pick neither of the options you've presented. Instead I would adjust the dose to be closer to double espresso flow rates (i.e., 50% to 60% brew ratio) and not worry about the brew pressure.

You could put a 500w or higher light dimmer switch between the brew switch and the pump power line. You get adjustable pump pressure, click on/ click off pump without triggring any 3way valve allowing for quick preinfusions at low pressure and long waits for the coffee puck to fluff up then click on and ramp up pressure for a nice controlled pour. With the preinfusion you dont have to do a lot of hocus pocus preparing the coffee in the portafilter... No WDT etc. Grind nice and fine, tamp and off you go. Hope you have a good grinder... pharos is awesome.

With any SB machine you can relieve pressure by opening the steam valve. I do this with my Silvia and I can adjust to 0 pressure. Takes a few tries but it's easy after that. I just allow a frothing pitcher to fill when pressure profiling and once I'm done I pour back into the water tank. This way requires no mods and wastes no water.