What’s this about? What’s the recipe? What’s the resultant taste profile? How does this compare to other espresso profiles? Is it better? What’s your testing / tasting experience?

Should I bother with this? (I’d have to reset the OPV to 6 on my Lelit E, or use a dimmer to do that).

Works well for some coffees. Not for all. Less body in the espresso. I was quite enthusiastic initially as it worked well with the bean I was using. I haven’t been able to replicate this with others.

I think the fundamental flaw in the study that made turbo shots popular is the assumption that flavour is directly correlated with a specific extraction ratio. You can achieve the same extraction ratio by grinding finer and a lower dose and high flow rate. It doesn’t mean you are extracting the same stuff.

  • MWJB replied to this.

    Emc2 Flavour balance/preference is correlated to any ratio that the extraction is possible at, you don’t extract anything significantly different from 1:2, 1:3, 1:4 you just do it at different strengths.

    I thought they were grinding coarser than they previously recommended for the “Systematically improving espresso” paper? (Hendon’s previous paper about grinding while frozen was favouring finer grinds. There was no paper about ‘turbo shots’. Previously 1:3 shots in 15-20s were called, “Shots”.

    • Emc2 replied to this.

      MWJB I was referring to this image. They suggest that once you find a tasty point, you can grind coarser and reduce the ratio. Alternatively you can reduce the dose and grind finer. Although the image says finer, I think it’s an error. It should be coarser as you say.

      The assumption here is that you are extracting the same stuff at a particular EY. This is not necessarily true.

      • MWJB replied to this.

        Emc2 The assumption here is that you are extracting the same stuff at a particular EY. This is not necessarily true.

        Sounds like one assumption being used to query another assumption. You are extracting the solubles available in that coffee, you can’t extract solubles from a different coffee. It’s not been shown anywhere that you an get components to queue jump. Of course, the non dissolved solids have an impact and one shot may have more/les than the other, but that is separate to extraction. Because two shots extract the same, this doesn’t mean they will also taste the same…similar, with similar overall characteristics, but not repeatibly the same.

          MWJB Agree. The same EY can be achieved in many ways but they aren’t necessarily similar in flavour. I do think however that flow rate can have an impact on what gets preferentially extracted. Not a perfect analogy, but with dialysis machines, the flow rate has a big impact on what toxins are removed.