Posted Wed Sep 26, 2007, 11:44am Subject: Re: Nuova Simonelli Oscar - new owner with questions, tips, & tricks
Here again is Dan Kehn's excellent article about HX machines (courtesy of home-barista.com). Dan has a boiler pressure --> boiler temp. chart that you can use in conjunction with a DIY boiler pressure gauge.
Remember that with Oscar's Sirai PStat, roughly 5-6 full turns of the adjustment screw = 0.1 Bar of pressure change. The Mater & CEME PStats are MUCH more touchy- like a quarter turn = 0.1 Bar change. Note that the above are boiler temps & pressures. Obviously, brew temps are lower due to heat loss, etc & brew pressure (controlled by the OPV) is independent from boiler pressure.
I've also attached Abe Carmeli's great write up regarding the regulation of brew temps via "cooling flushes".
e53er Senior Member Joined: 21 Apr 2002 Posts: 162 Location: L.A. Expertise: I live coffee
Espresso: NS Oscar, Solis SL90 Grinder: Mazzer Mini, Solis Maestro Vac Pot: Bodum Santos Drip: KMB, Hario V60 dripper Roaster: Poppery II
Posted Wed Sep 26, 2007, 11:45am Subject: Re: Nuova Simonelli Oscar - new owner with questions, tips, & tricks
Re: tapping off the fridge water line, I have been reading up on the effects of hard water on machine life expectancy. The hardness in my area is well above the 3 grains/50 ppm figure given to me by Nuova, so I think I'll start using bottled water. According to the Insanely Long Water FAQ, Crystal Geyser is a recommended brand. I also have a Brita water dispenser but I'll need a test strip to test for hardness after filtering.
dcforman Senior Member Joined: 25 Sep 2007 Posts: 68 Location: Columbus, OH Expertise: Pro Barista
Espresso: VAM Caravel, Nuova... Grinder: Nuova MDX, Nuova MCF,... Vac Pot: Yama 3 Cup Drip: Press Roaster: Ambex YM-2
Posted Wed Sep 26, 2007, 4:17pm Subject: Re: Nuova Simonelli Oscar - new owner with questions, tips, & tricks
Hey, new to the site (though I've been a barista for a few years now). I actually just won an oscar at a competition along with a NS MCF grinder. Pulled some decent shots off the bat, but anyway... I've been told that NS sells a hard line kit and a drain kit for the oscar. The guy who told me this claims to have both for his machine, so I don't think he's lying. Not sure of the cost, but it might be worth looking into.
caeffe Senior Member Joined: 30 Aug 2007 Posts: 271 Location: socal Expertise: I love coffee
Espresso: NS Oscar & Pavoni... Grinder: Mazzer Major / PeDe Moka Vac Pot: eSantos / Yama tabletop Drip: Krups Moka Brew / Bodum Kona Roaster: I-Roast 1
Posted Sat Nov 3, 2007, 6:15pm Subject: Re: Nuova Simonelli Oscar - new owner with questions, tips, & tricks
cdienzo Said:
Before messing with the Pstat though, I would try to dial in the grinder. I'm assuming you modded your SBUX grinder to grinder "finer" than normal, right? IIRC, a modded solis can produce a pretty fine powder.... Back it off a few notches and try for that ~30 sec. shot. Do the best you can with the plastic tamper, try to tamp consistently to 30#, but def get real one as soon as you can.
Once that's done, I'd move on to adjusting the brew pressure (OPV is directly to the left of the brew head. It has a tube at one end that leads to the drip tray.) and then the Pstat last.
Hey Chuck- It's been a couple of weeks now, rather than messing with my SBUX grinder I ended up getting a Mazzer Major, needless to say it was easy to dial in the grind.
I'm now trying to optimize the brew pressure & temp. Just finished making a press gauge, ended up having to take the basket off - pressure is pegged over 200 psig!!!
Where & how do I make this adjustment - it's not clear to me. If you got's pictures it would help. I can see the Sirai PStat but i'm not clear where the OPV is.
As far as brew temps, it was as you said - 180-185 F max. I'm using one of those digital meat thermometers - It's a trutemp brand. I'm not sure what kind of thermocouple it has but it probably has a slow response so I just make sure and soak it for a few times in the foam cup. I probably need to use something else. Be great if I can get a fluke type- maybe I can borrow one from work.
I guess the high pressure probably explains what i perceive to be a bitter shot. Never really knew this till I ordered an espresso at Kaffe in Orange.
Posted Sat Nov 3, 2007, 9:50pm Subject: Re: Nuova Simonelli Oscar - new owner with questions, tips, & tricks
ON ADJUSTING OPV'S: WET GAUGES AND NEEDLE VALVES:
Not shouting just a headline.
You can find a weksler gauge on ebay for short money a wet gauge (usually glycerine filled) is readable for a vibe pump.
the pressure will change as the flow changes. Put in a needle valve on the T assembled with a wet gauge, adjust the valve so that you espresso flow is approximated. You might want to run a drain hose off of the needle valve into a graduated vessel of some type.
This technology is inexpensive (if sourced on ebay) and will provide you with a much more accurate reading than a "blind" line with a gauge on it.
NO reason to spend $16 to do a less accurate job when you can spend a few extra bucks, do it right, and loan the tool to friends if you like. Perhaps they would buy you beer or bring by some artisan roast.
caeffe Senior Member Joined: 30 Aug 2007 Posts: 271 Location: socal Expertise: I love coffee
Espresso: NS Oscar & Pavoni... Grinder: Mazzer Major / PeDe Moka Vac Pot: eSantos / Yama tabletop Drip: Krups Moka Brew / Bodum Kona Roaster: I-Roast 1
Posted Sat Nov 3, 2007, 9:53pm Subject: Re: Nuova Simonelli Oscar - new owner with questions, tips, & tricks
cdienzo Said:
Once that's done, I'd move on to adjusting the brew pressure (OPV is directly to the left of the brew head. It has a tube at one end that leads to the drip tray.)
Ok, took off the top and took a picture and I think I located it. Shot is from the top with the front at the bottom of the picture, brew head right in the center bottom.
above link indicates that the OPV doesn't adjust the pump pressure? true or false?
if i do adjust, do i turn clockwise or counter? how many turns or degrees will get me a 1 bar or 15 psi reduction? which hex, the small one or the long one? I don't want to blindly turn things as the pressure i think is already way up >200 psig
also, the link indicates a way to measure pressure indirectly by the volume over x seconds, i'll have to try this method also as it's another way to dod the measurement w/o a gauge even though i've got one put together now.
caeffe Senior Member Joined: 30 Aug 2007 Posts: 271 Location: socal Expertise: I love coffee
Espresso: NS Oscar & Pavoni... Grinder: Mazzer Major / PeDe Moka Vac Pot: eSantos / Yama tabletop Drip: Krups Moka Brew / Bodum Kona Roaster: I-Roast 1
Posted Sat Nov 3, 2007, 10:09pm Subject: Re: Nuova Simonelli Oscar - new owner with questions, tips, & tricks
fifthgen Said:
ON ADJUSTING OPV'S: WET GAUGES AND NEEDLE VALVES:
Not shouting just a headline. You can find a weksler gauge on ebay for short money a wet gauge (usually glycerine filled) is readable for a vibe pump. the pressure will change as the flow changes. Put in a needle valve or the T assembled with a wet gauge, adjust the valve so that you espresso flow is approximated. You might want to run a drain hose off of the needle valve into a graduated vessel of some type.
This technology is inexpensive (if sourced on ebay) and will provide you with a much more accurate reading than a "blind" line with a gauge on it.
NO reason to spend $16 to do a less accurate job when you can spend a few extra bucks, do it right, and loan the tool to friends if you like. Perhaps they would buy you beer or bring by some artisan roast.
thx... i bought a needle valve and a t-fitting to do as you suggested - unfortunately i guessed wrong on the sizes and need to go back. as far as a dry/wet gauge - the gauge i bought eventually fills up with water, so maybe it is a 'wet' gauge. i can't tell if it bounces as right now it's pegged. thankfully it didn't burst....
i initially used this with the pf basket in place - it leaked like crazy but at least i can see the pressure somehow and did note that the needle bounced a bit...
caeffe Senior Member Joined: 30 Aug 2007 Posts: 271 Location: socal Expertise: I love coffee
Espresso: NS Oscar & Pavoni... Grinder: Mazzer Major / PeDe Moka Vac Pot: eSantos / Yama tabletop Drip: Krups Moka Brew / Bodum Kona Roaster: I-Roast 1
Posted Sun Nov 4, 2007, 5:35pm Subject: Re: Nuova Simonelli Oscar - new owner with questions, tips, & tricks
cdienzo Said:
Regarding the measurement of brew pressure, here a quick DIY that I saved from when I did mine.
The following is quoted from BillK from alt.coffee:
Loosen up the adjustment screw. To do this, remove the plastic drain tube from the nipple at the end of the valve. Then, use a couple of 3/4" end wrenches to crack the adjustment screw loose. Then, loosen the adjuster about 1-1/2 turns BEFORE you take any measurement - count nine or so flats on the adjuster.
I tried to turn the smaller hex but can't seem to budge it. Eventually the larger hex turned with it. I now have a back-up wrench holding the larger hex but i'm scared that it's taking too much torque to loosen.
Is there quite a big break-away torque on this valve? I'm afraid i might break something, especially some of the cantilevered plastic brackets close by....
Posted Sun Nov 4, 2007, 5:44pm Subject: Re: Nuova Simonelli Oscar - new owner with questions, tips, & tricks
i had the same fears with my ellimatic.. once i got that small nut loose, though, it was fine.. just hold the big assembly in place (I would recommend getting someone to help you) and torque will not extend to the rest of the machine.
caeffe Senior Member Joined: 30 Aug 2007 Posts: 271 Location: socal Expertise: I love coffee
Espresso: NS Oscar & Pavoni... Grinder: Mazzer Major / PeDe Moka Vac Pot: eSantos / Yama tabletop Drip: Krups Moka Brew / Bodum Kona Roaster: I-Roast 1
Posted Sun Nov 4, 2007, 7:50pm Subject: Re: Nuova Simonelli Oscar - new owner with questions, tips, & tricks
mitchellb Said:
i had the same fears with my ellimatic.. once i got that small nut loose, though, it was fine.. just hold the big assembly in place (I would recommend getting someone to help you) and torque will not extend to the rest of the machine.
success! took about 11 flats ccw before it got down to <140.
now another problem has popped up: after putting the overflow tube back on i get a big streaming leak right at the small/large hex i/f. looksl ike there's also an o'ring there that's been slightly displaced but if the tube isn't there i don't get the leak. turns out that the overflow tube is pinched too tight by a tie-down - i think it's causing some backpressure cuz when i put the overflow tube onto the nipple i get the leak and the pressure goes up to ~160. anyways, looks like i'll have to somehow try to clip the tiedown but its awfully tight in there. looks like the backflush tube is also pinched too tight by a tiedown also ....
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