Getting better! I think I was doing too much "fiddling" after the final tamp and breaking the seal. As mentioned in a a few recommendations above, nutating before the final tamp really seemed to clear things up.

In my opinion I might be blonding a little early. I do not have a video camera yet, so cannot post a video. Looking at other videos, however, it seems like the successful pulls are taking way over the classic 25 second recommendation. Any other Vivaldi owners prefer longer times for shots? [By the way, I have my volumetric set for 2 oz. Pressure is set at 9 bar. Not using preinfusion at the moment.]

JonF wrote:... it seems like the successful pulls are taking way over the classic 25 second recommendation. Any other Vivaldi owners prefer longer times for shots?

Yes. I prefer slightly longer extraction times on my Spaz S1, in the 30-35 sec range rather than 25-30 sec. I believe this is a consequence of the following*:

1) Al's Rule:
Most of my pours are mild ristrettos (brew ratio about 65%), and (according to Al) should be allowed to extract for a few seconds longer.

2) basket and grouphead geometry:
The bottom layers of grinds in a basket extract more slowly than the top layers, due to a vertical gradient of dissolved solutes in the puck. This effect is more pronounced in a tall narrow basket such as the 53mm Spaz double (which has the geometry of a triple basket).

* sheer speculation, of course

RapidCoffee wrote:I prefer slightly longer extraction times on my Spaz S1, in the 30-35 sec range rather than 25-30 sec. I believe this is a consequence of the following*:

1) Al's Rule:
Most of my pours are mild ristrettos (brew ratio about 65%), and (according to Al) should be allowed to extract for a few seconds longer.

Thanks for the reply--lots of variables to keep track of! When I see the time recommendations out there, it can be pretty confusing, especially if the volume is not mentioned too. Thus 2 oz in 25 seconds becomes WAY faster than a ristretto at 30 . . . Also, it seems that some start timing when the first drip appears, while some start when the switch is touched . . .

I do a 3 second pre-infusion and my shots usually run 35-40 sec (timed from when I hit the button) with no blonding. I'm not sure how much water my machine is set to dose volumetrically. I fiddled endlessly with the volume trying to get my preferred shot size and finally gave up. I couldn't figure out how to correct for water absorption by the puck. Using Al's brew ratio guidelines along with pre/post weighing has been super helpful. I've settled on a 50% brew ratio (14g dry/28g wet) -- which suits my palette, equipment, and preferred home/commercial roasts quite well.

RapidCoffee wrote:Yes. I prefer slightly longer extraction times on my Spaz S1, in the 30-35 sec range rather than 25-30 sec. I believe this is a consequence of the following*:

1) Al's Rule:
Most of my pours are mild ristrettos (brew ratio about 65%), and (according to Al) should be allowed to extract for a few seconds longer.

* sheer speculation, of course

John,

Am I close in guessing then, that for a 15.5g ristretto you'd end up with about 24g in 30-35 seconds?

Yes, that's correct. I typically weigh the coffee dose, but not the resulting espresso. The grind is adjusted to give me (approximately) a 30 second extraction. I use a 30 second kitchen timer for a reminder, but stop the pour using visual cues (shape of extraction cone and blonding).

The 65% brew ratio produces a "mild" double ristretto, which has become my standard espresso beverage. The volume is typically 45-50ml, and the result bears greater resemblance to a normale than the ristretto shots served in some third wave shops (which might extract even less liquid volume from 22g of grinds in a 58mm triple basket).

RapidCoffee wrote:Yes, that's correct (65% brew ratio). I typically weigh the coffee dose, but not the resulting espresso. The grind is adjusted to give me (approximately) a 30 second extraction. I use a 30 second kitchen timer for a reminder, but stop the pour using visual cues (shape of extraction cone and blonding).

So if I read the table correctly (ratios) the volume you collect, with crema, is slightly less than 1 oz? [Edit: Doh!!!, you had the volume in your post.]

By the way, thanks all for the discussion. This is helping a lot. When I look at most extraction videos, I do not believe that any are using the "2 oz in 24 seconds" rough guidelines I was shooting for. Two oz in 24 seconds, by contrast to the videos I have found, is essentially a gusher. My taste preferences have been towards the ristretto end of the spectrum.

No, typical extraction volume is 45-50ml (and 90% crema). Here's a pic I posted recently in another thread:

40ml and still going

(Sorry for the crossposting. I added the volume about 10 seconds before your post appeared.)

JonF wrote:Any other Vivaldi owners prefer longer times for shots?

It depends on the coffee. I find myself quite often around 30 seconds or above, below rarely. Yet - as I said - I find myself, that means I try to nail any given coffee for what I say tastes best and then I measure volume, time, etc. I'd had a blend two years ago that liked being pulled around 25s and high volume. The beans I had lately prefer long run - like a bit late cut off, past the normal blonding point.
I also had a coffee which pulled in the triple basket tasted better on higher volume, faster flow, then the usual slow triple ristretto way.

Yeah, I tend to shoot for 35 with my MVII. I have had some great shots that have been around 40 seconds.