I recently upgraded to a used DB (10 year old, but very clean La Spaziale Vivaldi S1V2) from five years with an E61 HX machine. Paired with Sette.

My shots are coming out very consistent, but lacking punch. Most drink are Americanos for me and lattes for my wife. Though straight espresso is on the bland side as well.

With the HX machine, I didn't have as much control, so I was usually adjusting things to tame overly strong sour or bitter tastes. With lots of control over temp, I'm not sure how to add back more kick.

Coffees I'd used with the HX machine, so no change there. Klatch Belle and Redbird Blue Jaguar. Both ranged from 5-10 days post roast.
Initially was using the stock double with bottomless portafilter. Then switched to an IMS Competition triple.

16-16.5g in the double (usually around 16g in 25 out, 30sec)
18-18.5 grams in the triple (usually around 18g in 26 out, 30-33sec)
WDT on all shots. Flat and Convex tamper used. Occasional mild channeling, but usually pretty good.

I can taste the swing from sour to bitter as I go from low temp to high, but still can't get much in the way of bold tastes to cut through in Americano and Latte.

Brew pressure seems okay. Tested with a gauge, but was having trouble getting a good reading. Seemed to be around 9bar. (Also, gauge on machine reads a little shy of 10bar during brewing, so at the grouphead is probably close to 9bar).

You might need to actually raise your machine pressure and grind finer. Did you notice if you had to coarsen your grind for your DB? Going about this with a math approach, the 53 mm portafilter experiences about 17% less force through the surface area compared to a 58 mm portafilter, given the same pump pressure. To match the same force through the portafilter, you'd want to increase pump pressure to around 10.5 bar. Flow rate would go up so then you'd fine up the grind.

Another way to look at it is this - if you held the grind the same from the get-go, and dosed more into a 58 mm portafilter to match the same puck bed depth as that of the 53 mm portafilter, your espresso machine would be choked out unless it had more pressure.

I can't find where to quote from, but intuitively it makes sense that more pressure = more intense flavors, especially if you compare to, say, regular gravity brewing. I'd see if adding pressure might help. Also I cannot speak to the specific coffees as I've not used those before, and also you've said you've kept that constant so it's unlikely the coffees or other variables have changed.

+1. Can you grind coarser and dose higher? That will punch things up.

Or just sell the machine to someone struggling to tame 3rd wave coffees; they'll pay its weight in gold.

I've got some lighter roast in the freezer Was planning on getting the hang of the machine to not waste it, but may need to switch to it.

I had updosed a bit, but hadn't pushed it too far. I'll see tomorrow how far I can go [was experimenting with temp adjustment this AM and got to caffeinated to try anything else].

another_jim wrote:+1. Can you grind coarser and dose higher? That will punch things up.

Or just sell the machine to someone struggling to tame 3rd wave coffees; they'll pay its weight in gold.

+1 I use Jim's guidelines that he generously shared years ago.

Eg. Too fine and small dose and the sweet might cancel out the other flavours. Try backing off the fineness.

Sour is a completely different beast from sweetness and acidity. Sour is a temp issue.

Be careful about getting caught up in multiple sets of measures that have different impacts.

Grinding fineness is one scale
Temp is another scale
Pressure is undoubtedly another scale

Just to add to what others have suggested, for the ims competition basket's recommended dose is from 18-22g - I would dose more to see what you get, start at 18g and keep on going up, once the espresso opens up then play with yield to get the flavours you want.

Thanks all for the suggestions to keep upping the dose.
I think I'm getting closer to the max dose. I'm at 19.5 grams, but getting much more channeling and the center takes longer to start flowing. The massive bolt in the middle of the Vivaldi group is going to be the limiting factor, but I'll try 20/20.5 grams and see how it goes.

Even with the channeling, taste is much better. Richer and deeper.

Had an americano at a cafe this weekend which was really amazing (they use stumptown coffee, but the americanos at the stumptown shops near me aren't as good). Gave me a good data point and extra motivation to keep pushing.

After going through a lot of coffee, I'm making some progress.

I tried up dosing in both the triple and double baskets, but was getting increased channeling as I pushed it higher especially with a coarser grind.

So I went back to square one. Seems with the grinder and machine I've got, I should be able to make drinkable espresso from the coffees I was using (grabbed some hairbender in addition to the Belle and Blue Jaguar). I ultimately decided something wasn't right.

I made three changes:
1) I rechecked the pressure and lowered it a little from low 9s, to lower/mid 8s to see if this would help with the channeling. This led to minimal change.

2) I adjusted the offset so I could crank up the temperature. This seemed to be the missing link. I think the temp was way too low. I don't totally understand why it didn't taste more sour, but upping the temp is making the shots look right (and taste right). Previously the pulls looked thin as if the coffee was older. Now I get a nice moderate cone develop, which I would expect from 4ish day old coffee.

3) To combat the channeling, I lowered the dose which meant I could get rid of the dosing funnel and WDT. I dose straight in till the correct weight. Tiny shake to level. Bit of a tap with the tamper on the side if needed. Moderate tamp with convex tamper. I've even had good luck with dosing till a pile, leveling off flat, and tamping...tends to give a very consistent 17grams every time. The high dose and the funnel were causing channeling which the WDT helped prevent, but now I can pretty much dose and go.

What is also refreshing...I'm now getting the occasional terrible shot. Previously I couldn't make a good or bad shot. They all tasted flat.

zfeldman wrote: 2) I think the temp was way too low. I don't totally understand why it didn't taste more sour, but upping the temp is making the shots look right (and taste right)

If the temperature drops below 190 or so, the shots taste slightly sweet but not much else. It's an unusual problem, so none of us thought of it.