I've only had the Mini Vivaldi for a few days so I'm still getting used to it. But one thing I've noticed is that the coffee comes out slow at first and then gradually comes out faster. And it looks a little thin to me. Some other videos I see are not that way at all... some other vids show a thicker, gloopier consistency.

This is a 22 second pull. When I go finer grind, it starts off a very thin, slow mouse tail. Almost choking it. But I can get closer to 30 seconds.

About 16g dosage. Each shot glass had about 19g output.
Red Bird Espresso, 6 day old roast.

Thoughts? Recommended adjustments?


(HD available)

How did they taste?

I only encountered this kind of flow when:

1. The coffee is getting old (grind like 1 hour ago)
2. Low dose coffee and tighter grind tend to have a thinner flow
3. Too high a temperature that also result in a super fast and bitter shot.

For me option 2 seems realistic with the 16g dose. Doesn't mean that your shot is bad but more of a side-effect of low dose extraction. But if it taste bitter and unbalance with an underdevelop coffee, than up the dose and grind coarser

It was a little sour and acidic for my style. Not terrible, though.

When I grind finer, it's better, for sure. And the thin mouse tails at the start are even thinner. Red Bird even recommends a 25-30 sec shot, beginning from first drop. It just looks weird for it to start so thin.

Did you check with the temperature first?

Your describing an under-extract shot, and a profile that doesn't seem like Red Bird

bamaster wrote:It was a little sour and acidic for my style. Not terrible, though.

When I grind finer, it's better, for sure. And the thin mouse tails at the start are even thinner. Red Bird even recommends a 25-30 sec shot, beginning from first drop. It just looks weird for it to start so thin.

Do you see any signs of channeling on top of the puck? You might be well served by a naked portafilter, so you can see how the extraction comes together in the beginning.

What I would do is grind coarse (until the shot just comes flooding out), then go finger click by click until you slow it down.

Check the temperature also, as mentioned.

How hard are you tamping? Sometimes less is more with tamping.

Ray

Marc wrote:Did you check with the temperature first?

Your describing an under-extract shot, and a profile that doesn't seem like Red Bird

The temp is a total educated guess, at this point. I'm just using the settings that others have had success with. 92*C with +3*C offset.

I have a pocket digital thermometer on the way. At least I can get some temp readings with a styrofoam cup.

RayJohns wrote:Do you see any signs of channeling on top of the puck? You might be well served by a naked portafilter, so you can see how the extraction comes together in the beginning.

What I would do is grind coarse (until the shot just comes flooding out), then go finger click by click until you slow it down.

Check the temperature also, as mentioned.

How hard are you tamping? Sometimes less is more with tamping.

I haven't really studied the puck but they are dry and no signs of fractures. As for tamping, I would say I'm on the shy side of 30 lbs. No nutation. Very slight, quarter twist at the end for polish. I'll post a video of my technique in a bit.

bamaster wrote:I haven't really studied the puck but they are dry and no signs of fractures. As for tamping, I would say I'm on the shy side of 30 lbs. No nutation. Very slight, quarter twist at the end for polish. I'll post a video of my technique in a bit.

Based on my experience with my La Pavoni and a naked portafilter, it's almost all in the grind of the beans. Myself, I would lighten up a bit on the tamp and fiddle with the grind. That usually produces good results for me, when I'm dialing in a new bean.

You really should invest in a bottomless portafilter. Channeling issues and/or uneven extractions manifest themselves far more readily on the bottom of the basket, than on the top.

Ray

Too fast, too much final drink. (for my liking)

On Dalla Corte machines with 54mm baskets, I found that 17.5-18.5 was a great starting point for dosing. So, I would up the dose, and then coarsen until you get a good flow rate, then start tasting and adjusting the grind to taste. The shot you pulled looks pretty overextracted to me.

EDIT: Oh and start the shot as soon as you can after locking in the portafilter. You can grab the shot glasses after. (and sorry for reviving an old thread)