Grind, humidity, temperature woes?
So just for the last week or two, we've had all this humidity and crazy weather in Brisbane and it has coincidentally come at a point where I've switched to a new bean and can't seem to get a (correct or) fine enough grind. The grind level got to the point that if I pushed it any more the blades would be touching and audible. I can't remember what the bean (thinking Columbian Pitalito but I change every week so it get's confusing) was but it was at most 2 weeks post roast. Just wondering if there's any relation to my issues here.
I haven't had a problem with dialing in the grinder for any other beans and generally they're all around the same grind level (a step or two out at most). I haven't changed my technique and always tamp to the same level (which admittedly has given me soupy pucks but good tastes? so I didn't bother fixing that). My wife somehow manages to also get a decent coffee successfully without changing any grind settings for all the other beans we've tried and now she also gets a underextracted sour coffee. The brew pressure sits around 6-7 generally but usually it goes to 10 for a 27 sec extraction.
So I went searching for problems. 1. I've cleaned out the grinder thinking there was something not right there. No real issues. I do hear a slight sound, but only sometimes, of the blades touching when I switch to a specific grind setting. Eg turn to grind level 18 - no sound. Next day.. turn to same grind level - blades scuffing noise. Does this mean the blades aren't level? I don't think it's possible to crossthread the entire upper portion of the grinder when placing it back in.
2. Also cleaned out the shower screen and the usually chemical backflush etc. The machine is only 3-4 months old so I didn't think it was an issue but thought the pf wasn't sealing well. No issues here either as far as I could tell.
I was reading humidity and temp shouldn't affect the grind that much but I'm not sure what else it could be. I may have to try testing the grinds on my finger next round.
Gonna go back to some Ethiopian Harar tomorrow to see if that sets it straight. Any suggestions would be most appreciated.
I believe you've answered your own question Tim, change coffee and see what happens . If it all goes back to normal then it was that coffee, and I would have done that first. If it is the coffee, the reason why will only be a lot of academic conjecture with no real explanation, starting anywhere from that the quality of the green bean supply could have been sus, to anything thats happened to it from there to your grinder.
Originally Posted by mitt
Hehe. We'll it definitely was the coffee. The Ethiopian went through without a problem. Hmm might roast another batch of the other stuff to test it out again.
What could do that to the green beans exactly?? Just out of interest. Bit of a waste if it's not something I've done
I was recently given some local grown beans roasted by the grower. Had exactly the opposite problem, and had to keep winding back the grinder to stop it massively overextracting.
Spoke to the grower who suggested probably due to difference in bean cell structure between softer low grown to imported harder & higher grown. Imagine processing methods also played a part. Had to tighten up grind again for my own usual roasts. He also gave me some green so will be interesting to see if I have similar results when I roast them.