Problem pulling shots with Lelit Bianca + Eureka Mignon XL

Beginner and pro baristas share tips and tricks for making espresso.
kast0r

#1: Post by kast0r »

Hello,

I bought my Lelit Bianca last weekend. (I upgraded from a Lelit Grace). This machine is very beautiful and very complete. However, since I got it, I have had a hard time making good espresso.

Lately, I found that the flow of coffee that was flowing was slow and very little crema or even no crema. I did a manual pre-infusion at around 2-2.5 bars for about 15 seconds and then I increased the pressure to 8-9 bars. The espresso took about 60 seconds to make (18g in, 36 out. The 15 seconds of pre-brewing is counted in the 60 seconds total)

I was advised to grind the coffee more coarsely. Thing I did. I now come to 30-35 seconds total for a 36g shot in the cup. There is a little more crema now. On the other hand, the problem I have now is that since I changed the grind, I end up with channeling during the extraction.

My puck prep looks good. I grind the coffee with the Mignon XL, then I use the WDT OCD v3 to dispense the coffee into the naked portafilter and then tamp.

But I have inconsistency with my shots since the change of grind, even though the taste and the final result of the cup is better than before.

I'm not sure what to look for to allow better extraction. Once again I have the impression that the flow of flowing coffee is a bit "slow" but I find that it is more the quantity that flows more than the flow as such.

Do you think a WDT like for example Levercraft Ultra WDT could fix this problem or I could validate something else first?

Thanks very much!

cgibsong002

#2: Post by cgibsong002 »

You might have over corrected on your grind now. At 30s total with 15s pre infusion, that could be a bit fast. It's hard to say without knowing the coffee you're using. If it's a really light roast, your original shot was probably on the mark. If it's a medium or dark, 15s pre could be too much. What are you tasting though? What is bad about it? I would advise maybe starting with standard shots without the flow control until you learn your new machine.

As for wdt, yes it will help. I don't know if any research that has shown wdt to be detrimental. OCD on the other hand has been proven to lower extraction. Which could be good or bad depending on the coffee you're using.

Pressino

#3: Post by Pressino »

If you are really accurately dosing (weighing), distributing, and tamping (as level as possible), the coffee may be the culprit...staleness being a factor. Anything more than 3 weeks post roast, unless scrupulously stored, is going to be more or less stale. One of the first things to go will be crema, which depends on gas (mainly CO2) released during extraction, and which is released from roasted beans over time).

Secondly, how do you know you are channeling? I recently got a new machine and decided to use a naked PF to observe extractions and noted a few "spritzes" that I thought were due to channeling...turns out the basket I was using had several blocked orifices. I cleaned the PFs with Joe Glo and spritzes were greatly reduced. I stopped using the naked PF, however, since it is practically impossible to totally eliminate occasional errant spritzes and I decided the pleasure of watching the swirling extraction tail was not worth the trouble of constant clean-up...There are some hints you can get about channeling by observing the extraction through a naked PF, so what is it you are observing (if you use a naked PF)? Or did you diagnose channeling by examination of the puck?

Finally, pre-infusion may be either helpful or detrimental to an extraction, depending on how you do it. One of the benefits is supposed to be that low pressure infusion consolidates the puck and thereby minimizes the risk of channeling when full brew pressure is applied. While this may be true, there are a lot of variables, including in your case how you are adjusting the flow during extraction with the Bianca's FCD. You could be promoting rather than minimizing channeling.

Smo

#4: Post by Smo »

No one can give you perfect advice.
There are too many variables in the espresso preparation process.
Only your work and experience will give you an excellent result, in a couple of years, until you open a bag with a new type of coffee in search of perfect beans ...