Hi again,

I decided to remove the wire from the jet as the water flow was too low. It took ages to cool down the machine before a shot and the results in the cup weren't very special (maybe slightly sweeter). The good thing was that the group wasn't flash boiling at all!

I will try to dig up a 0.4mm and a 0.3mm wire and see what results that gives.

Regards,
dsc.

cannonfodder wrote:With the stock Elektra 0.9mm jet I get 4.225 ounces by weight in 7 seconds with no portafilter.
....
I went with the 68 main jet, perfect fit. I reassembled the group top (one bolt) turned on the water and ran the same test again. I am now flowing the same 4.225 ounces in 9 seconds; I have slowed the flow rate by two seconds.

Dave, I decided to apply your mod, as I'm interested in slowing the pressure ramp-up out of the group. I got a #65 and 2 #68's, one for Tom (I am sending him some PID parts at some point). Anyhow, I got the 3 jets, and they came all 3 in the same bag... (to their credit, they shipped the parts faster than any company I have ever dealt with, and no, they aren't that close to me). I looked at them quite closely and had great difficulty picking out the smaller one, but I think I did so. I put that one (#65) in my group. I filled up my EPNW shot glass to the top, which I assume is about 4.225 oz., in 11 seconds. I don't have a Scace to check the before & after ramp up.

I'm about to pull some shots and see if I can get some improvement. At a variety of doses (oddly, the down-dosed shots in particular) I have been struggling with early channeling. My shots always come together after 10-12 seconds, but that first 5 seconds is pretty irksome to watch, and it's definitely correlated, at least somewhat, with some really harsh notes on the front end of my shots. When I say somewhat, I mean that in the sense that I suspect my brew temperature is a little inconsistent owing to the nearly .5 bar deadband on my boiler and my complete unwillingness to "boiler pressure surf" a machine of this caliber.

Anyhow, thanks for the tip on this; I'll post more later.

Well, an hour and a few shots later, I'm liking this. The channeling at the beginning of the shots is diminished or eliminated so far, at doses of 15 and 16 grams. I'll be going lower and see if I can get better results. Not that this is particularly interesting in general, but with this coffee, Brown Coffee Co's Espresso Three (Note: as of this writing, it's not available on their site), I am getting better results at 16 grams over 15, even now. However, I'd say that both doses cleaned up with the new jet. The 16 gram doses have a clean acidity, with a pleasant semi-sweet, powdery baking chocolate flavor. The 15 gram doses are similar, but the chocolate is not as sweet.

More testing is certainly in order, but I've got to go out of town for the weekend, so it will be awhile.

Hi Nicholas,

I'm struggling with my low dosed shots as well and I might go back to the smaller jet config simply to see how it manages bigger doses of 15g-16g. In my case it is a bit different as the shots start quite well (although that might be because of the added in-line preinfusion) but usually end in a mess. Coarsening the grind screws up the beginning as well and making it finer chokes the machine. I've noticed that I'm getting the best results with coffees which are 5-10 days old and afterwards it all slowly goes bad with each day. I have to say though that with the smaller jet the shots were definitely sweeter which is good news and something to look forward to when the new jet arrives.

Regards,
dsc.

Hi Nicholas,

are you still using that jet in your machine or have you switched back to the old one?

I've installed mine yesterday and I have to say it's very slow, taking 15-20s to cool the HX from idle. The group doesn't flash-boil at all (nice thing), but I'm not so happy with the results in the cup. It might be due to the fact that I'm using 14g doses with the Ritual Vitamin D and that coffee is quite heavy, which means the dose is quite small volume-wise giving it I think a bit too much room. I will bump it up to 16g to see if it gets any better, now it starts well but goes down the gutter midpour (blonding/channeling).

Regards,
dsc.

How do you mean, you don't get any flash boiling? I still get a decent bit, albeit less. I haven't noticed any real changes in the cup, other than maybe a marginally improved forgiveness factor. I would be extremely hesitant to attribute 'negative effects' to the new jet, considering all the other stuff you've been doing in the past few days...

Flushing does take a lot longer. I programmed in my initial flush, so I flush it initially while I get milk or do something else, then come back and build my shot, flush again (shorter), and go.

Hi Nicholas,

yeah I doubt it's the jet, it's probably my fault, but you know it's always easier to blame the part:)

I haven't done too much damage during the last few days:) hopefully it will stay this way for the next few as well.

Regards,
dsc.