Good morning! I've been working on "dialing in" my new setup for a few weeks and I'm starting to get frustrated with my extraction times changing despite all else being the same (to my knowledge). Here's my setup and my process:

Equipment:
- ECM Classika PID with flow control
- Baratza Sette 270wi - Has ground about 4-5 lbs of coffee and I installed the included shim after the break in period
- Asso The Jack Leveler
- Espro calibrated 30 lb tamper
- GDEALER scale
- Lavazza caffe espresso beans from Costco (I know it's not the best, but I didn't want to waste good coffee while setting things up)

Process:
1. Smart outlet turns machine on half an hour before I use it. PID set to 200.
2. Grind 17 grams, shake it, level it with the leveler, and tamp it with calibrated tamp
3. Pull the shot while timing from first drip and watching the scale. I try to stop around 34 grams

Problem:
Sometimes the extraction is 25 seconds, then pull another shot and it's 17 seconds, then another and it's 30. If it gets too far off, I make small adjustments to coarseness of the grind until I'm in the 20-30 second range again. Then eventually it gets off again. Any ideas? How consistent are your extraction times?

Trying to save with old beans is like driving with flat tires saving air. It does not work. Italian beans can be 2 years old, and one month is what we are looking for...
If like italian coffees taste, you can put a bit of those in fresh good stuff. If I can get hands on with "fresh" italian beans, I can go up to 50/50. -But I'd still not recommend that for calibrating anything.

Even with very stale coffee if your prep is identical, there should not be that much variability.
Work on your prep as it is not consistent.
Single charge or hopper on the Sette?
Weight of beans in the hopper has more effect the fewer there are.
Do you purge the Sette for each shot?

For a fresh classic Italian this is as good as it gets: Wolf Coffee Organic Espresso.

I also agree with fresher beans. The old beans are difficult to use and not to mention will be lacking in flavor. It can be a little disheartening to go through multiple baskets of more expensive coffee to get the settings right but you will probably find that it may not take as much adjusting as you think. I also have the sette 270Wi and I buy fresh beans from a local roaster. Most of their beans end up being a similar grind setting so it's normally only a matter of adjusting the micro adjustment dial (A-I) and rarely the larger numbered dial. I'd recommend finding a fresh coffee you like and work with that. You'll find that once you get that down, most other fresh beans (of similar roast level) will fall somewhat close to that grind.

I just recently decided to give WDT a try and it has helped a good bit with consistency. It's easy and cheap to make your own if you're interested. Personally, I bought these needles and used a pair of pliers to push them into a wine cork : https://www.amazon.com/dp/B07KC6VTDF/r ... UTF8&psc=1

For the grinder, I assume you're getting consistent weight in the basket after grinding? That would be the first thing to check for but I assume you've already done that given the sette weighs the dose for you. Given the variance in extraction times, one would think the issue has to be in the bean consistency, basket prep, grind, or a combination of all 3.

ping279 wrote:You'll find that once you get that down, most other fresh beans (of similar roast level) will fall somewhat close to that grind.

News to me.
The same roast from the same roaster and the same beans can vary markedly between seasons.
Beans age and humidity varies affecting the roast even though the Agtron is identical.

The old beans you're using, which I imagine are roasted dark, are likely quite brittle and could be producing random amounts of fines. Fines have a big impact on flow rate. As others advised, get some higher-quality fresher beans. I'd lean toward a medium or medium-dark roast for learning how to dial in your equipment.

If you're using the hopper with your grinder (i.e., not single dosing), the grind will change as the weight of the bean column above the burrs decreases. Fewer beans in the hopper will require grinding finer. Alternatively, make sure you have a constant level of beans in the hopper.

That said, you reported that the shot time can go down and then up. Unless you added beans to the hopper in-between the second and third shot, something else is wrong. Again, the most likely culprit is the beans.

My impression from a few posts I've seen is that the Sette isn't super-consistent. Others can chime in with opinions on that.

cafeIKE wrote:News to me.
The same roast from the same roaster and the same beans can vary markedly between seasons.
Beans age and humidity varies affecting the roast even though the Agtron is identical.

I was just speaking from personal experience; you may be right on the beans in general. I also might not have noticed the change from season to season as it could have been small gradual changes over time possibly? Using the same grinder as OP, I've found that I can keep grind settings somewhat close together when switching to a different bag. I guess it also depends on your definition of wide variation. The local roaster I use does vary but I've been able to keep the sette on the same macro setting for the most part, while only changing the micro adjustment.

Italian coffee that has been sealed for months off gases very quickly once its opened, this creates a moving target for the first few days. You can certainly try another coffee, though I would also verify the accuracy of your Sette's doser. Weigh out the grounds it produces for a while to make sure it is giving you a consistent dose within 0.2g or so.

Failing those, a couple other things to possibly consider:
* how clean is the shower screen? If parts of the shower screen are gunked up this can cause the water to disperse unevenly, causing intermittent channeling. It's happened to me a few times where my shots started getting inconsistent and it was resolved by removing and cleaning my shower screen.
* is there any possibility your preinfusion pressure or time could be changing?
* how temp stable is it from shot to shot?
* finally, is there something in your prep that could be causing it? Perhaps replace the shaker and leveler with wdt.

Hi 15W40,
I'm no expert just a regular person. I read through all the replies as of this reply and notice no one asked and you didn't mention if you are purging the group head between shots? I have a much lesser espresso machine but find that purging the group head between shots does 2 things 1. Cleans out shower screen and 2. Stabilizes the brew temperature. It waste water but so does pulling inconsistent shots.

Regards