New Lelit Bianca --Advice on isolating variables?

Beginner and pro baristas share tips and tricks for making espresso.
regalzack

#1: Post by regalzack »

Hey!

So I recently upgraded to a Bianca, and I figured it's time I go back to square one and re-evaluate things.

My plan is to isolate one variable at a time until I can digest its role before moving onto another.

First up is ratios. I want to play around with 1:1,1:5,2.0 & 2.5 to to build an intuition beyond just higher for light roast/lower for dark roast.

I guess my question here is what is the best standard flow profile for this? I'm thinking a standard 9 bar extraction is the simplest, but I'm not sure If I ought to use the paddle to maintain a constant 9 bar through the entire shot or let it naturally taper off towards the end of the shot? The goal I have in mind here isn't necessarily how to make the best tasting shots, but the most consistent so I can focus on the variable that I'm changing(ratio) to observe it's affects.

I think once I get accustomed to the changes that ratios make, I can start playing around with pre-infusion, profiling, temp, etc. It just seems logical to start simply on the variables that have the largest effect and work down into the minutia.


Any advice would be appreciated!

Pressino

#2: Post by Pressino »

Except for the flow control device, there is nothing special about dialing in espresso with the Bianca. The variables are the same: beans, grind, dose, puck prep, machine settings (mainly pump pressure and brew boiler temperature), and extraction till you reach the desired brew ratio.

There are many videos on the internet that go into great detail about "dialing in" espresso. Also quite a few discusses here on this board. :)

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Ursego

#3: Post by Ursego »

regalzack wrote:I'm thinking a standard 9 bar extraction is the simplest
The simplest, but the worst. Constant flow rate is the worst thing you can think of for espresso. :twisted:
regalzack wrote:but I'm not sure If I ought to use the paddle to maintain a constant 9 bar through the entire shot or let it naturally taper off towards the end of the shot?
Try my favorite profile (which is a combination of the "blooming" profile and "sweet bump" profiles):
  1. Fully open the faucet and start brewing.
  2. When 5 seconds are on the timer, completely shut off the flow.
  3. When 35 seconds are on the timer, open the faucet to "7:30".
  4. When 50 seconds are on the timer, open the flow to the maximum.
  5. When 55 seconds are on the timer, return the faucet to the "7:30" position.
  6. Gradually decrease the flow until the valve is almost completely closed (this step will be short as there is not much time left).
This profile allows you to make delicious espresso even from beans roasted a long time ago (as an experiment, try the cheapest beans from the supermarket - you won't believe the results!)

Vindibona1

#4: Post by Vindibona1 »

Ursego wrote:The simplest, but the worst. Constant flow rate is the worst thing you can think of for espresso. :twisted:

Try my favorite profile (which is a combination of the "blooming" profile and "sweet bump" profiles):
  1. Fully open the faucet and start brewing.
  2. When 5 seconds are on the timer, completely shut off the flow.
  3. When 35 seconds are on the timer, open the faucet to "7:30".
  4. When 50 seconds are on the timer, open the flow to the maximum.
  5. When 55 seconds are on the timer, return the faucet to the "7:30" position.
  6. Gradually decrease the flow until the valve is almost completely closed (this step will be short as there is not much time left).
This profile allows you to make delicious espresso even from beans roasted a long time ago (as an experiment, try the cheapest beans from the supermarket - you won't believe the results!)
For those of us who don't own Bianca's is it possible for you to post the water debit (mL/set) from your 7:30 and "wide open" positions? That way I (we) can figure out where the flow control positions need to be on our individual machines. It sounds very intruiguing if I can mimic your water flow.

Also, what temp are you brewing at? Do you have a standard dose that you use? Dose to yield ratio?

Thanks in advance!

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another_jim
Team HB

#5: Post by another_jim »

regalzack wrote: My plan is to isolate one variable at a time until I can digest its role before moving onto another.

Any advice would be appreciated!
Don't.

Espresso, like all life is finding a good routine. Play around until you are comfortable in the routine. Then do variations on it. You are in a multivariate state space that includes prep variables and taste variables. If you feel you must move in straight lines, work out how you need to change all the prep variables to go in a straight line on one taste variable at a time.

Would you drive a car around using only the steering wheel, then only the gas peddle, then only the brake; or do you drive it tryng to go straight, accelerate around a curve, etc? Would you prepare a soup by only chopping the onions and carrots, or only boiling the water, or only putting the pot on the stove, and seeing what happens? The people who give the one prep variable at a time advice are so busy repeating what they've heard they can't even think aboit the implications of what they are saying.
Jim Schulman

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Ursego

#6: Post by Ursego »

Vindibona1 wrote:For those of us who don't own Bianca's is it possible for you to post the water debit (mL/set) from your 7:30 and "wide open" positions? That way I (we) can figure out where the flow control positions need to be on our individual machines. It sounds very intruiguing if I can mimic your water flow.
"7:30" - 4.6 gr/s, fully open - 6.5 gr/s.
Vindibona1 wrote:Also, what temp are you brewing at?
96C (205F) with dark (but not very dark) beans. It's higher than 92C (198F) I would use without blooming, but the temperature is dropping while the coffee is blooming (since all the water is going back to the tank), so it's cooler when the main extraction begins.
Vindibona1 wrote:Do you have a standard dose that you use? Dose to yield ratio?
19 gr in - 40 gr out (using 20 gr VST basket).

Notice that you need to grind finer for Slayer shot (long pre-infusion), and even finer for blooming.

Vindibona1

#7: Post by Vindibona1 »

Ursego wrote:"7:30" - 4.6 gr/s, fully open - 6.5 gr/s.

96C (205F) with dark (but not very dark) beans. It's higher than 92C (198F) I would use without blooming, but the temperature is dropping while the coffee is blooming (since all the water is going back to the tank), so it's cooler when the main extraction begins.

19 gr in - 40 gr out (using 20 gr VST basket).

Notice that you need to grind finer for Slayer shot (long pre-infusion), and even finer for blooming.
I didn't see your reply before trying the recipe using "Kentucky windage" for the dose, grind and waterflow. I did 18g in 20g IMS basket (which I like better than my VST) w my normal grind, but the timing was way off an all I know is that full open now is aroung 5mL. I leave my brew temp at 200°F for most everything. Before the time was up I had 63mL of coffee in the cup, so I'll have to regroup and figure out the flow rate. Actually is was't half bad. Maybe a little thin. I did just now, after the fact, measure flow from the positions I used ans was pretty close; 4.4mL and 7mL.

I'm a little surprised that your Bianca full open is 6.5mL/sec. I'd have thought that it would be higher with the rotary pump. If I had to fully close the valve on the FCD on QM67 I would not have been able to get close to 6.5mL, but now can go fully to 8.5mL as I have 360° rotation after modifying the paddle. I would have purchased the Bianca when V2 was still available except that the tank mounted on the rear would have made it stick out too far on the counter and I didn't have enough room on the side for it. It was definitely on the short list.

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Ursego

#8: Post by Ursego »

Vindibona1 wrote:I'm a little surprised that your Bianca full open is 6.5mL/sec. I'd have thought that it would be higher with the rotary pump.
Mine is ECM Puristika with vibratory pump. We we just discussing flow control regardless the machine.

Vindibona1

#9: Post by Vindibona1 replying to Ursego »

I see. I printed and tried your recipe and the timing turned out to be a total fail for me. I imagine I would have to figure out different paddle positions for the timing. Obviously the pre-infusion/wait time is a given. But once I turn on the pump the pre-saturated puck just let 'er rip, regardless of how fast tried closing the paddle. With a straight shot, close to 6.7mL flow I'm genrally about 30 seconds. have to try something different.

The one thing I've noticed is that you're brewing at 205°F. I haven't tried brewing that hot for medium roast beans. I've been solid at 200° an at 18g for roughly a 2:1 ratio and only primarily messing with how fine the grind is. Perhaps I should explore the higher temp? I've been in the ballpark for good shots, but I know it could be better.

Thanks for your input.

Pressino

#10: Post by Pressino »

We need to remember that the PID indicated brew temperature is not the same as the temperature in the brew chamber and unless you actually measure the brew chamber water temperature you will not know how it relates to the PID temperature setting. This is true even when manufacturers provide a temperature "conversion" offset. This offset is at best an estimate (i.e. educated guess) because, at least in an e61 machine, the brew chamber temp will always be a bit lower than the brew boiler temperature, given the machine's operating environmental conditions, and the manufacturers are basing their guestimate on presumed standard conditions.

That's one of the reasons to try to measure, as accurately as you can, the actual temperature of the brew chamber water.