I've seen and read through a few threads on body & clarity differences of different machines (DE1, BDB, E61, La Spaz, LM, etc etc).

For the purpose of this I'm looking at clarity and body being two ends of a spectrum, where an increase in one is a trade-off of the other. And body meaning texture and viscosity rather than tasting notes, whereby same grinder and coffee on a "high body" machine would produce more mouthfeel and more muddled flavors, and on a "high clarity" machine the same coffee would have less mouthfeel and more delineation of flavors.

Although there didn't seem to be a definitive consensus answer on what causes a machine to have higher body or clarity, there were a few consistent hypothesis:
- shower screen height / headspace, where more headspace = more clarity
- flow rate, where higher flow rate (8-12ml/second +) = more body
- preinfusion, where longer slower preinfusion = higher body

Has there been any more work done on this, or any more insights from anyone? I have an Alex Duetto, E61 rotary plumbed, and am borrowing a BDB to test out at the moment. I have an 804 with SSPs and drink almost exclusively light/ultra light coffee (Sey, Sample, Wendleboe and similar) and am chasing clarity. I'm not convinced the E61 is going to be the best option for me hence testing the BDB. The BDB seems higher in clarity, and that coincides with what others have said here.

I compared shower screen height thinking that could be the cause, but they look to me to be the same!!!


I have flow control on my Duetto so set the flow rate and pressure at the puck identically on each, but the BDB seems to flow a touch faster and produce more clarity. But why?? If all those parameters are the same? Could it be copper boiler, brew line, and group head of the Duetto vs the stainless boiler and plastic tubing of the BDB? Any other ideas??

Clarity "versus" body, regardless of the espresso machine or brewing method, has been discussed in detail and quite well in a tread on HB started by Marshall back in May 2013. I suggest reading that thread, which I take to suggest that: 1) the relationship of body and clarity is complex and not necessarily antagonistic; and 2) the particular beans used, roast level, grind features, and extraction parameters play a much more significant role in clarity and body of extracted espresso than the particular machine one makes it with.

Forgot to cite the thread: Is body the enemy of clarity?

Thanks for the thoughts and link to that post. I had a quick read through and while I agree that those factors you mentioned will have a larger impact on clarity and body, it's a bit different to the question I'm asking. Sorry if i didn't explain myself well, but essentially I'm asking:

What are the factors at play that cause one espresso machine to be higher in body and another to be higher in clarity, given the same coffee, grinder, dose, ratio etc.

It has come from me tasting the same coffee, dose, grinder, ratio etc on two (and more) different machines and perceiving a difference in clarity that can only be down to the machines.

jb-0101 wrote: ...essentially I'm asking:

What are the factors at play that cause one espresso machine to be higher in body and another to be higher in clarity, given the same coffee, grinder, dose, ratio etc. It has come from me tasting the same coffee, dose, grinder, ratio etc on two (and more) different machines and perceiving a difference in clarity that can only be down to the machines.

OK. Given what I said (or rather what was said in the HB thread I referred to), I suppose the answer to your question is that whatever differences in the clarity and body you perceive in shots drawn from different machines would be due to differences in the extraction variables (mainly water temperature, pressure and flow rate over time, and total extraction time). Differences in portafilter size and geometry will also come into play.

If you're looking for an answer like "Machine A produces espresso with more body (and/or clarity) than machine B" I think you're going to be disappointed. Certain generalities could be made, as there are definite differences in the espresso produced by lever versus pump machines and between pump machines with different heating methods and group types, but those differences are going to be related to how those machines affect the extraction variables I just mentioned. The recent development of pump machines with flow/pressure control has to some degree leveled the playing field in regard to the ability of different machines to produce espresso to one's individual tastes. There are also some simpler espresso "machines," like Moka pots, the old Atomic, as well as more complicated consumer espresso makers (I won't name them) that do not offer enough control of extraction variables to allow you to allow you to consistently control the taste/body qualities of the espresso they produce.

Some folks here may offer you advice about the ability of specific machines to produce "better" clarity, body, or whatever other taste parameter you care about, but I won't go there.

Under variables listed above I would add characteristics of the basket bottom (hole diameter, number, total hole area) and shape (cylindrical, tapered)

Sorry yes forgot to add that parameter - I used the same basket on both.

So yes I understand that different factors can have an influence on whether you get more body or clarity, but that's not what I'm referring to - I'm referring purely to the machine. So all other factors being equal, what it is it that causes some machines to emphasize body over clarity and vice versa?

There's a thread about Decent vs E61 that goes through a bunch of ideas, but it's fairly well established in that thread that the decent (and the BDB is referred to in the same camp) produce less body and more clarity than an E61. There was speculation that shower screen height is a factor, and while it may well be, the screen heights of my E61 and BDB are the same, so what else could it be?

It could be that brew temperature and and intra-shot brew temperature profile play a role.

I know that double boiler E61 machines have an offset on the order of 5-7C between the boiler and the group, given the fact that the group sheds 60-70W of power continuously when it is at temp. While I haven't scoured any recent Scace data to suggest what this does to the sh** temperature profile, it is safe to expect that with the heated and tucked away group on the BDB, that the scace performance will be different.

Have you experimented with hotter or cooler brew temperatures on either machine to see if the differences you perceive are amplified or muted?

Another suggestion to rule out any cognitive bias is to pull blinded shots into identical cups when testing, or even perform triangle tests, where two shots are from the E61 and one from the BDB and then another batch with two from the BDB and one from the E61. Can you consistently tell the two machines apart? It can be eye-opening when you are certain that these two have more body and this one has more clarity and then you look under the cups and see that you have 1 cup from each machine grouped together and one of the paired shots from the other machine as the odd one out.

Assuming you rule out biases and you can confidently identify the BDB every time, the other thing that differentiates these machine could be the water distribution. Not sure if you dabble with puck screens, but they could be something you could use to take distribution out of the equation. Same goes for paper filters under the puck.

Cheers!

-Jake

I would suggest looking at saturated group heads and non saturated.
Makes a huge difference in my opinion to my taste the saturated brew head IE LM group head were the water tube that the water is pump through is surrounded by a water bath of near precise temp water as is pumped through the tube and out of the group head makes a massive difference.
I personally think saturated groups bring more body and texture for sure.
I prefer more body and texture over supreme clarity.
Flat burr verses conical has an impact here all though larger 80 to 100 mm flat burrs get closer to equalling conical results.
I have always preferred conical myself.

Considering the thermal stability of the BDB, once upon a time this machine was Scace tested and found to be one of the best espresso machines out there with a PID tucked right in the group head. Would that produce better clarity...maybe?