After experimenting with some different blends from different roasters now I have somewhat better understanding about how drastic the difference can be between different beans (even between artisan specialty beans with the same origin coming from different roasters).

So I have found beans which can produce enjoyable cups. However I have a feeling that there is still a lot of room for improvement for me, as in many cases the unground and ground beans have absolutely magnificent smell, while the drink in the cup is ok but not great at all, missing all those beautiful smell components of the bean. In many cases even the spent puck has a much better smell than the drink itself, which tells me that lot of goodness remains in the puck. (btw. is this(bean and puck having better smell than cup) a usual/expected outcome or an indicator of a fault?)

Can you pls. give me some advice what might be a logical next step to improve my cup?

Current workflow:
- 2 to 4 weeks old bean immediately put into freezer after bought in original bag
- switch on machine(Sage/Breville Oracle Touch/PID, OPV, heated grouphead, no pressure nor temp gauge) 10-30 minutes before making a drink
- just before making an espresso, take out bag from freezer, measure out one dose with 0.1g scale, close bag(not airtight anymore), put back to freezer
- blank shot with empty basket to rinse/preheat cup and grouphead/portfilter
- grind with 1Zpresso K-plus with a setting which produces roughly 1:2 yield in 25-30 sec. (usually I try different yields and times, but I didn't feel drastic differences in taste, so this is where I usually end up). 19g ground coffee in an IMS nano 18/20g basket.
- put coffe into portafilter from the k-plus "blind shaker" catcher, using it's anti clogging bottom
- WDT
- no tapping or knocking in any step
- tamp with palm tamper set to fix depth, haven't changed depth since months(so tamping pressure should consistent for the same ground coffee)
- put portafilter into Oracle, start a manual shot, stop it based on weight at 1:2 yield (take notes if I need to change the grind level next time to keep time between 25-30 sec)

Visually I think the extractions look fine, but I will upload a fresh video.

The Oracle doesn't have a pressure gauge, so I am not monitoring pressure at all.

What might be a good step forward?
-try another grinder (e.g. a Niche Zero, or something else?)
-try another machine which provides more measurement options(pressure, temp) (a La Pavoni with SEP or an Odyssey Argos with bluetooth profiler?)
-a high end tamper like The Force?

I have already ordered an Acaia Lunar, so at least I will be able to monitor the flow rate soon.

The comment about the spent puck smelling nice is a red flag for me. Mine just smell wet and woody.
I use a robot and something I do is smell and taste the excess water that is pressed out at the end. It's been a great way to to check if I should pull a given coffee a bit longer.
You could try a similar experiment: get some cups, say five, start a shot, and switch cups every 10sec or so. This will give a rough picture of what flavors are coming when in the pull.

You're still dealing with old to stale beans to start and not keeping them in something airtight is likely making things worse.

@Miltonedgebert, thank you for the great advice with the salami shot, I will get into of habit of trialing with that regularly!

@Jeff, many thanks for pointing this out! I thought that bean age and storage wise I am ok now with freezing them when bought, without giving too much attention to packaging (I thought it doesn't matter if the bag is airtight if it's frozen anyway).
I am glad there is room for improvement here.
Can you pls. give me advice (or a pointer to a good advice) about the best way to store the beans? Roasters around here usually pack their stuff in those 250g/500g aluminium bags with grip closure and air valve, so that's how I receive the goods.


Also I was thinking that freezing 2-4 weeks after roasting is ok. Usually that's the age when roasters deliver their stuff around here, but I will try to get even fresher stuff then.

For medium-roast coffee, around 10 days to two weeks is probably an OK time to start the bag. If you do get ahead of yourself a bit, I'd tape over the one-way valve before tossing into the freezer. Those valves are not the most reliable things for sealing. Four weeks after roast for a medium or darker is getting past where I usually enjoy them. Light roasts can often go a bit longer than medium or darker roasts. I don't know how your roasters define "medium" as there isn't really any official standard that roasters adhere to. For me, if it is "espresso roast" it seems to almost always end up what I call medium or darker.

If in a 250 g resealable bag and you consume coffee at around 40 g a day, that's around a week. For that, taping over the valve and using the seal on the bag is something that I do. I'll keep a week's worth on the cool counter, out of the sun, in a sealed bag or jar. At 500 g, I'd probably split it into a canister for the week and a sealed bag in the freezer for next week.

There have been discussions around if one should remove and replace a bag or jar in the freezer. I don't have a strong opinion one way or another. I do find that frozen beans grind very differently than room-temperature beans, so being consistent there means always using the same timing if you're pulling them from the freezer. A basket of beans seems to me to warm up pretty quickly, though I haven't stuck a thermometer into one to know if that is a couple minutes, or 10 minutes, or longer

Thank you very much Jeff, very useful advices, which I will definitely incorporate into my routine.

Seeing that you have a KPlus, what is your experience/opinion, is that proper for espresso? (I've seen the opinion at some places that the steps of KPlus are too large for espresso. My experience is that one click can cause a 10 seconds difference sometimes, other times it causes no difference at all, or maybe changes the time in the unexpected direction... but then that might be because I don't tape the valve on my frozen beans, or the humidity changes, etc.)

Long story short, how do you feel about KPlus for espresso in general?