Last few days with no change to beans or grind or water (temps or volume) the resistance has greatly increased on the arms. Could this be due to humidity changes? As we move into winter it gets much drier around here.

The ground coffee looks a little clumpier and doesn't tamp as easily - I'm using a Silenzio, cleaned about 3 weeks ago, doing 2-3 coffees a day.

Espresso is still tasty, but a lot more work!

There's lots of reasons why beans grind differently over time. Adjust your grind settings to suit.

Also consider only using beans in the range of 10-30 days after roasting. And put the minimum amount of beans in the hopper and store in a proper, sealed coffee canister.

Well, I've had this set up successfully producing shots since mid summer after dialing in the Silenzio.
Did I imply I was using old beans? I buy 340gm bags from a local Italian roaster that sells through their own deli/butcher/grocer/bakery. They have a high turnover rate and I use the bag up within a week or two, though honestly beans that are too fresh can be as much of a problem as those that are, by date, stale.

My hopper holds 250gm of beans, I just ordered the bigger size to accommodate the whole bag.

On my Kafatek, the same bag of beans as they age over a few weeks will require a fair change in grind setting to maintain my desired extraction time.

Different beans often require significant grind setting change, even the same beans from the same roaster but a different batch.

Hm, my beans have almost never needed any real adjustment, might be down to how dark roasted they are.
Regardless, dropping the dose has made the extraction a bit easier (as would grinding coarser, of course) but I was curious as to this unprecedented (in my experience) change.
Cheers

ojaw wrote:Last few days with no change to beans or grind or water (temps or volume) the resistance has greatly increased on the arms. Could this be due to humidity changes? As we move into winter it gets much drier around here.

From what I've read the more common observation is that an increase in humidity decreases the flow, requiring a coarser grind. I don't know if this is real or just another one of many coffee myths.

One thing to consider is whether it's really drier right now. Relative humidity usually goes up in colder weather since less moisture is needed to reach saturation. If the issue is how much moisture the grounds are absorbing, that absorption correlates with relative humidity, not absolute humidity.

Perhaps it's a temperature effect? Maybe something to do with your grinder? Or maybe there is some seasonal effect with the roasting?

Can you close off your kitchen and adjust temperature and humidity to simulate summer conditions?

jpender wrote: From what I've read the more common observation is that an increase in humidity decreases the flow, requiring a coarser grind. I don't know if this is real or just another one of many coffee myths.

One thing to consider is whether it's really drier right now. Relative humidity usually goes up in colder weather since less moisture is needed to reach saturation. If the issue is how much moisture the grounds are absorbing, that absorption correlates with relative humidity, not absolute humidity.

Perhaps it's a temperature effect? Maybe something to do with your grinder? Or maybe there is some seasonal effect with the roasting?

Can you close off your kitchen and adjust temperature and humidity to simulate summer conditions?

Though it is true that outdoor humidity goes up in the cold, our winters get cold enough to require big differences (up to 60º C) in outdoor to indoor temps and so our INDOORS become very dry in the winter months. Our gauge, my hands and my wife's hair can attest to this.
Might be a seasonal effect on the roasting, though like I said the espresso is still tasting good and the beans don't look any lighter/darker or oilier/drier. It might be that storage conditions for the beans before they get to me have changed, but then again I noticed a difference in the middle of a batch.
Our kitchen is open to the living room, basement and mud room so difficult to isolate.
I'll give the Silenzio another clean up after this batch, see if that makes a difference.
Regardless, everything still works, I just get more of a workout.

How is everyone doing!!! I wanted to report back on my experience! I am on week 7 of my Robot. I cant believe its been over a month! So far, I love it! Thank you all for answering all my "Pre" and "after" questions.

Here is my report so far: Love it but hard to figure the balance for Crema with my Kiny M447 Grinder.

I took the advice of everyone here and went back to my beans. 100% correct my beans were a bit too old. Here in NYC we have some good roasters so I took the advice and went toSey Cofee in Bushwick and bought a few bags. I am currently using Piedras Amarillas beans from Honduras. They are a bit pricey ($23 for only 250g) but the packaging is really nice . For a Baseline I also ordered an espresso and a drip coffee with this bean so that I would know how they make it. So far, I have not been able to replicate their machine pulled espresso. It had a bit more Crema and maybe a slightly "Stronger" taste. FYI I still like mine though .

My current review thoughts then Method:
It's fun, almost like a meditation every morning and it honestly has been giving me something to look forward to during this pandemic. I really want to thank Ken for helping spur me along with my Pm's and checking in. I honestly did not want to write in until I gave myself some solid time. I like what people said about the review by Sprometheus http://www.youtube.com/watch?v=feCGRsMu8ug I don't see how you can understand this machine in 1-2-3 days let alone even 2 weeks. Novice pro. I feel like this wonderful machine is like taking someone out on a date. Except you only see the kinks in the beginning. Then you break it in and every day gets better leading up to new discoveries. Then you take a taste and its like Wallah! YuM!

I may not have the perfect cup, but I would like to figure out the right grind setting with my Kinu M47. Maybe it's the part of me that dislikes wasting money with good beans when I am learning but lets discuss the method and you all can decide:

Method:
1. Measure 16-18g into my Kinu M47
2. Grind Setting 1.5.8 (I start at 1.5 and have gone as low as 1.4.2 and high as 1.6.2)
3. Heat up water in my Le Creseut Tea kettle until it whistles
4. Grind Coffee
5. (Optional) Heat Portafilter. In the beginning I always did this. Now, I can't seem to "taste" a difference. It may be my buds are not as refined as all of you as I am "Newer" to this coffee world .
6. Place grinds into Portafilter
7. Use the end of two Nespresso scoop spoons together with the thin wand end into the filter to mix grinds for air bubbles.
8. Tap Portafilter on table again if off.
9. Use new Tamper and turn to blend in
10. Put on New Screen
11. Tilt to the side and let water trickle in so it does not disturb grinds (first time I did this my water was black). Then even out to about 1-5mm from top. (If too little water like Hoffmans 60g I get no resistance ---- WAS A HUGE ERROR in the begning).
12. Place into Machine

Pull Method
1. Pre infusion at 1/2 - 1.5 bars for 10-15sec. I usually stop when I see a drip.
2. Ramp pressure to 6 and hold.
3. OPTIONAL I try 8 bars but hard to see a difference and confused here
4. Hold until done
5. Release once the pull shows thinness like water

Nespresso Barista Maker Froth
- If you own one, the ONLY Milk that will pull good froth in the US if you don't make your own is Oatly Barista Edition. I legitimately tried 17 brands and none could get froth. This one is the only one that makes a froth worth chatting about. Specifically in this machine. I like this machine as it makes it much easier and hey, I like these things.

1. Set to Cappuccino or Flat White
2. Place on top of Espresso if that's what I want

Thoughts / Questions :
1. Pressure wise, should I be holding @ 6 - 8 bars? Or is this too low?
2. Am I obsessing over creama more so than anything else? When I first came to the site I LOVED the look of the "Bloom" where the Espresso had this fine silk like velvety flow and it honestly was sexy.
3. My beans are a light roast. With my Kinu M47 has anyone had luck with certain settings for specific beans with this machine?
4. For Shits and giggles I put my Kinu to a 2.0.2 and did a Moka Pot.... WoW Still true, it was like going from Andre Champagne to Ace of Spades. This Grinder alone was a game changer. With the Cafelet Robot it's like losing your virginity.

Would love any feedback and I think this is a big text so if you made it this far I thank you for your patience. I hope this really does help some people and I will check in for responses and in another 7 weeks I bet I will have a few more things to add. I think my MAIN DIFFICULTY is my Grind, figuring out which grind for which bean and if I am using too much or too little pressure.

Thank you so much everyone!!!

Bombadilio wrote:Pressure wise, should I be holding @ 6 - 8 bars? Or is this too low?

Paul has spoken at length on this subject, 6-7 bar seems to be the norm for most lever machines and his is no different.

Ignore the crema, go for taste. Medium and lighter roasts usually don't have much crema with any machine or technique. Check James Hofmann's "crema" video for some insight.

6-8 bar should be fine. That's the range I extract medium and lighter roasts most of the time. Going much over that and you end up in a strange place where more pressure can result in less flow, not more.

If you're getting overly sour results, grinding finer and/or a higher temperature can sometimes help. Grinding finer usually means you need "solid" puck prep (perhaps something finer for stirring and leveling, 0.4 mm acupuncture / 3D-printer-cleaning needles are in vogue right now) and even, early infusion to help reduce channeling.

Sey coffee usually roasts very light by US norms. Make sure you let it rest before trying to pull shots. I don't know their recommendations, but a couple weeks or longer would be my g guess.