Jake_G wrote:I would say the Scace emulates a nominal shot puck resistance, rather than ideal. This is because actual shots are not constant flow in the slightest, therefore they are not constant pressure since the pressure drop across either the gicleur in a standard machine, or the profiling valve in aptly appointed machines such as ours is proportional to flow (technically to the square of the flow, but who's counting ). At any rate, this explains your next comment.



I don't own a Bianca, but I use a similar mechanism for profiling shots on my modified Rancilio S20 and it is typical for the peak pressure after puck saturation to be higher than what you measured with the Scace. This is because the flow is so very low when the puck is saturated and has not yet begun to erode. This low initial flow gives you pressure closer to what you'd see with a blind filter basket than what you'd see with your Scace basket. I wouldn't worry about your grind setting and would continue to follow your taste buds to the correct profiles.

Cheers!

- Jake

Jake,

This is also quite helpful, thanks! With my former Expobar HX machine I greatly preferred Capps over shots, as it was a little brute force in extraction, only had the pressure ramp built into the vibe pump, and even though I had Eric's thermocouple in the group, temp control was finicky at best depending on how long the shot ran.

Now I am finding shots on the Bianca to be incredibly expressive, but also realizing that I'm sort of starting at square one in evaluating these new shots on taste and adjusting the grind, temp, or profile in response. With great power comes great responsibility, I guess!

I read your entire thread, and learned a ton. Thanks.

No. Set the paddle to 1/3, grind and dose it right, and you'll climb to 8 to 9 bar (after about 15 to 20 seconds) then drop to 5 or so by the end of the shot. (the panel manometer should be reading about 11 bar, the factory setting. You don't want to mess with this, since it reduces the control you get at the needle valve)

Just pulled a shot like that. Put the paddle roughly at 1/3, which is where I've been setting for preinfusion. The shot behaved like you describe, and I pulled the shot at around 28g for a 16g dose.

Very mellow shot. I was making a Capp, but tasted it first. The shot got lost a little in milk, but still enjoyable. The previous shot was better in milk- that one I started just like this one, but once I got some drops from the basket I put the paddle almost full over, then towards the end of the shot back to 1/3. Dedinitely a punchier shot, and maybe more like a Slayer style shot?

Definitely interesting to experiment.

The fascinating range and adjustability of the Bianca was one of the main reasons I chose it to be my main source of the daily unfolding coffee experience. However, that adjustability can also be a very big space to wander around and get lost in. Here's a shot profile I've developed that allows me to reliably dial in my grind setting for different roasts and establish a base, to work out from:

I start with a medium/fine grind and dose about 16g on a darker roast or 18g on a light/medium roast. Or follow the roasters recipe if you have one. This gives a small headspace of around 2mm for the 18g dose on Bianca which can be filled in 2-3 seconds with the paddle pointing outwards, around 90 degrees(to the panel). Starting with this paddle position, swing left after this first 2-3 seconds, or at the first sign of needle movement on the grouphead gauge. Vary the paddle position towards fully closed/ low flow, to keep the gauge creeping up to 2bar, over 5-8 seconds. This timing may be longer, if you have started with a tight or fine grind, but you'll be able to control it with the paddle position and wait for a "natural" pressure rise.
This phase of low pressure preinfusion will naturally end with the gauge pressure rising above 3 bar, as the puck fills, swells and develops resistance to flow. Drips may start at this point.Then follow the gauge pressure upwards with a slow movement of the paddle rightwards, increasing flow, but keeping the pressure under control up to 8 bar or so. If the grind is in roughly the "right" zone for control, you will be able to increase pressure and flow up to full now by paddle movement rightwards, or limit to 8 bar or so and decline at the end for a softer "lever style" shot.

You can then let taste and flow rate, measured by the shot timing, be your guide to make grind adjustments. I still find it useful to refer to Espresso 101 and taste charts, but broadly, if the shot is bitter it may be flowing too slowly and over-extracting. You can loosen the grind a little. If it's bland or sour, fast flowing or lacks control with the paddle, tighten the grind.
If you are measuring flow rates, there is a rate that shows up repeatedly in my notes as being a good tasting space to begin and it is around 1g/second, measured from first drip. Thus, a 40 second shot, with 10 seconds to first drip would yield around 30g. None of this is intended to be definitive, but to be a helpful starting space.
I like to use a Kinu M68 hand grinder for this because it has repeatable fine control, with 1 line adjustment = 0,015mm of burr adjustment. 2 lines or notches will get me a shot timing change of around 3-5 seconds. But I can also reproduce this process, using a Ceado with 68mm flat burrs. I often trend downwards from a 50 seconds or so start point to a 35-40 seconds or so shot duration, as the flavours and mouthfeel improve. This obviously depends on the roast, beans and personal preferences.
From a good tasting space here, there's a whole range of shot profiles and temperature/time variations to play with!

That's a good base profile; close to a classic E61, but useful with finer grinds.

I find the thing I vary most now is the preinfusion time, letting the machine sit at 2 bar with a slow drip into the cup for anything from 5 to 25 seconds. This directly changes the extractions, so that the longer peinfusion shots are taste gentler, the shorter ones, more in your face. Quite frankly, this is a less fussy then changing dose and grind, as outlined in the 101.

A couple questions and a request . . .

I have been thinking of upgrading my Vivaldi, and this looks like a super option. Thanks all for the detailed user experiences. Just a couple easy questions for any owner:
1. How do you find steaming ability? I steam one large latte for my wife every morning . . .
2. Hot water? I am guessing this is straight boiler water, but wanted to confirm.

Finally, a favor: I have a bit of a height limitation in my kitchen. I have seen height measurements listed as "approximate" but can one of you please take two measurements for me? Just the full height of the metal side and the height to the top of the wooden pressure paddle. Thanks much, Jon.

I hope someone else isn't away for thanksgiving, I'll have to pass on precise counter height (whoever checks, also see if the feet adjust)

The steam boiler is only 1.5 liters, but you can get it up to 1.75 bar (2 bar with a programming hack on the PID adjustment). I find it steams faster than the Strega's 2 liter boiler set to 1.25 bar. However, I only do 5 ounces of milk at a time for cappas, which takes under 10 seconds; I don't know what it would be like doing 3 or 4 lattes at a time.

The hot water is straight from the steam boiler. However, with the rotary pump and powerful brew boiler heating element, you can run a a pint of hot water from the group without the machine breaking a sweat.

^^ thanks!

JonF wrote:A couple questions and a request . . .

I have been thinking of upgrading my Vivaldi, and this looks like a super option. Thanks all for the detailed user experiences. Just a couple easy questions for any owner:
1. How do you find steaming ability? I steam one large latte for my wife every morning . . .
2. Hot water? I am guessing this is straight boiler water, but wanted to confirm.

Finally, a favor: I have a bit of a height limitation in my kitchen. I have seen height measurements listed as "approximate" but can one of you please take two measurements for me? Just the full height of the metal side and the height to the top of the wooden pressure paddle. Thanks much, Jon.

I make a lot of Capps, steaming up in a small 12oz jug. I have the steam boiler at 1.75 bar with the smaller holes tip and it's great. With the larger holes tip I'm blowing milk out of the jug, even turned down to 1.3 bar. You should be fine steaming lattes.

I can measure the machine when I get home later today.

Quick measurements between Nutcracker performances today:

Top of the machine: 14 7/8"
Top of the paddle: 15 3/4"

My feet are adjusted all the way down, so these should be the minimum heights off the counter.