Seeking group wisdom: Nuova Simonelli Oscar

[sorenk]

To all;
I have a question for the group, one that is like a thousand asked every day on coffee/espresso sites, yet, one with which I still struggle. I take as starting assumptions that every machine and grinder are different (in some way), and that no two setups will produce the same result. That being said, I ask for guidance.

In brief, I have a (new for me) used Nuova Simonelli Oscar and a refurb Baratza Preciso (direct from Baratza). This is a dial-in/shot/extraction/grind concern that is beginning to bother me. In particular, the Oscar produces a 'pulsing' broken stream and rarely a steady, creamy stream. The conditions for my question are:

Things I have tried:
1. Re-calibrated grinder (i.e. moved the adjustment screw) to the finest setting
2. Tried steps 1-10 (macro) and every other micro step at each macro step
3. weighed coffee each time (16g)
4. Used 2 lbs of fresh beans (roasted 2-4 days) [I realize that post-4 days is best, but I have tried the pre-grind and wait 20 mins process as well. The results didn't seem any better]
5. Followed the process for the Oscar in terms of allowing enough time for it to heat up and flush between shots. It has been descaled and backflushed this week.
6. As best as I can, I tamp with equal pressure.

The results:
1. From steps 1-3, the shot takes between 60-80secs (measured from time I push the button to start the pump, and 2oz)
2. From 3-6, the shot takes between 45-60 secs
3. From 6-9, the shot takes between 20-45 secs. Now, I know the 'ideal' is between 20-30secs, but the pour isn't a steady flow, but a series of 'pulsing flows' that blond at the 1/2 point. The taste is flat. It's the best (at say 6G), but compared to the Gaggia Classic (using the Encore), body and flavor are seriously missing.

I am aware that factors like humidity, the type of water used, and the variety and age of the beans impact a shot. But, it seems strange that I can't get close to a decent pull, one that I can tweak using a micro step or two.

I welcome any advice and help the group might provide.

With much thanks,
Lyndon

[grinderz]

I'm no expert on the Oscar, but we have one at work. I was never super impressed with it. To be honest, I haven't used it all that regularly because it because the grinder (NS Grinta) is usually full of stale beans, but even when I've brought good beans from home, I've never had a stellar shot from it. That could be just me not driving it very well, though.

[donn]

The results:
1. From steps 1-3, the shot takes between 60-80secs (measured from time I push the button to start the pump, and 2oz)
2. From 3-6, the shot takes between 45-60 secs
3. From 6-9, the shot takes between 20-45 secs. Now, I know the 'ideal' is between 20-30secs, but the pour isn't a steady flow, but a series of 'pulsing flows' that blond at the 1/2 point. The taste is flat. It's the best (at say 6G), but compared to the Gaggia Classic (using the Encore), body and flavor are seriously missing.

This is internet advice at its worst, since I haven't ever used an electric pump machine ... so I hope this isn't an annoyingly obtuse question, but where do these 9 steps come from?  What is step 6?  I'm wondering if your pull is about 4 times as long as it should be.

[grinderz]

Have you played with temperatures much? The Oscar is a heat exchange machine, so it's pretty easy to pull a shot with water that's way too hot. If you're new to HX machines, this may be informative:

http://www.home-barista.com/hx-love.html

[sorenk]

The results:
1. From steps 1-3, the shot takes between 60-80secs (measured from time I push the button to start the pump, and 2oz)
2. From 3-6, the shot takes between 45-60 secs
3. From 6-9, the shot takes between 20-45 secs. Now, I know the 'ideal' is between 20-30secs, but the pour isn't a steady flow, but a series of 'pulsing flows' that blond at the 1/2 point. The taste is flat. It's the best (at say 6G), but compared to the Gaggia Classic (using the Encore), body and flavor are seriously missing.

This is internet advice at its worst, since I haven't ever used an electric pump machine ... so I hope this isn't an annoyingly obtuse question, but where do these 9 steps come from?  What is step 6?  I'm wondering if your pull is about 4 times as long as it should be.

No worries. The 'steps' are taken from the grinder settings (1-40 'clicks' that adjusts the fineness) of the Preciso. According to Baratza, steps 1-10 ought to be sufficient for most espresso machines.

[sorenk]

Have you played with temperatures much? The Oscar is a heat exchange machine, so it's pretty easy to pull a shot with water that's way too hot. If you're new to HX machines, this may be informative:

http://www.home-barista.com/hx-love.html

Thanks, yes, this was a post I reviewed a number of items before purchasing the Oscar. The flushing required between shots demonstrates just how hot the water gets. Even in the crappy shots that I have pulled, the temperature of the espresso is considerably higher than what I am use to from the Gaggia Classic. That being said, I still need to work on the temperature question.

[peter]

I can't speak to your equipment, but suggest throwing the 20-30 second rule out the window.  I get shots at 45-60 seconds that are perfect, and they're ristrettos to boot.

[John F]

I know nothing about that machine but my guess is that either your pump is wonky or you are not building a stable enough basket for a "smooth" shot.

You could see gushers and choked shots depending on grind/tamp but pulsing... . something is wrong. My guess is the above items.

[sorenk]

I know nothing about that machine but my guess is that either your pump is wonky or you are not building a stable enough basket for a "smooth" shot.

You could see gushers and choked shots depending on grind/tamp but pulsing... . something is wrong. My guess is the above items.

Right, it's the kind of flow (the pulsing) that has me baffled. I can accept the need to refine grinding, tamping, etc., but from near chocking to crazy short shots, it's the unstable flow that strikes me as odd.

I'm don't particularly have the gadget-opening/hardware tweaking in my skill-set, so I have contacted a local service place near DC to investigate what a proper examination and service of the machine might cost.

[sorenk]

I can't speak to your equipment, but suggest throwing the 20-30 second rule out the window.  I get shots at 45-60 seconds that are perfect, and they're ristrettos to boot.

Sage advice. Thanks.