Morning Gentlepeople.
As a coffee newbie I am having some small issues while trying to improve my game. I have a Oracle Touch and subscrube to a local monthly coffee delivery, so my beans change weekly.
My issue is that the grind setting is incredibly different from bean to bean. With my last bag, grind 14 gave a perfect 1:2,5 ratio. With a different bean today, I had to discard two cups before learning that grind size 3 gave me the same ratio. 14 gave me 1:3,5 which tasted rubbish.
The problem is that I got channeling and very little crema.
I guess the questions are: do different beans require completely different ratios or am I doing something very wrong?
Should I accept a very high ratio to avoid channeling on certain beans?
Or should my timer be lower on certain beans?
Thanks in advance for any help and have a great cup this morning!
Grind settings are widely different for each bean, it’s normal. Depends on a lot of factors (origin, variety, altitude, roast etc).
Lighter roasts tend to need slightly longer ratios (~1:2.5 to ~1:3.5), darker roasts shorter ratios (~1:2). Faster shots (20-25s) are usually fine.
As for channeling issues, puck prep is of paramount importance but I’m not sure how much prep you can introduce in this machine’s workflow. Counterintuitively, channeling is often caused by grinding too fine, but the water rushing in the channels actually make the shot much faster. If you can WDT between grinding and tamping, it would solve a lot of issues.
Thanks for the feedback.
Sadly the tamping is integrated in this machine so I have no say in it really. No way to disable it and do manual only, so only more would be possible after the machine is done.
My shot time now is 28 seconds static, just to have a baseline and adjust grind to match weight afterwards. All are medium to dark roasts. This is following James Hoffman’s review of the machine.
Apart from the channel, the coffee tasted good. I am mostly concerned with constantly fidling with the grind to achieve a consistent result.
What would you have tried in my case?
Decrease shot time with coarser grind and ignore the lack of crema?
Cheers!
constantly fidling with the grind
…is a necessary step on the way to great tasting coffee. You just have to decide if it’s worth the effort for you. Those kind of super-auto machines are better suited to slightly darker roasts and just getting the same consistent beans every time.
The short answer is that there are a lot of variables, so your process has to be dialed in per bean, which is why most people end up just sticking with 1 type of beans.
Different roast levels are going to have different densities. Different bean varieties (and localities) are going to have different density and size. The age of the bean comes into play as well.
Some variables affect the actual brewing, others affect how the beans grind. Every once in a while, i’ll have a bean that just seems to make more fines for whatever reason. I guess it’s just down to the stiffness of the bean and the size.
If you want to be able to switch beans at will, you’ll need to keep notes for each variety, and adjust back and forth as needed.
I don’t think you’ll be able to get a new bean right on your first shot no matter how you try to adjust. If you adjust for one variable, there’s still all the others.
It’s starting to dawn on me that you might be right.
I think I’ll keep trying different beans to test a lot of different coffee before landing on one variety and order that instead.
I’ve gotten a lot of really good advice here today that I’ll use in my future brewing career.
Thanks for taking the time, mate!
James Hoffman has a great video (or even series I believe) on “dialing in” espresso machines, definitely worth watching.
That’s also my key criticism with buying subscription coffee, often they send quantities that are too small to get to a meaningful brewing routine. I’ve had a gifted subscription for 150g monthly, and I was going through 30-40g just perfecting the output. So by that time I was left with enough coffee for 2 weeks and had to resort to alternative sources.
It might help to know a little more about the actual beans. Depending on the roast those ratios might indeed vary greatly, I’d think.
These are quite dark. Other than that, I know very little about them.
I’d go crazy and say similar roast to the supermarket beans I get great results with at 14 grind, if that is of any use?
Cheers!
The darker the roast, the lighter a bean should be. You could count a number of beans you have your numbers right and get decent results with, weigh them, and thus compare their roast to that of other beans. That way you‘d be able to find out if your achieved ratios are tied to the roast. Maybe you could even work out a scale telling you what to expect, a ballpark to get your ratio somewhat right when opening a new bag of beans.
That said, I’m only citing theory here, don’t take what I say as the last word on anything :)
Ok I just did a quick weight test and the difference is massive!
The store bought beans are marked 6/7 darkness and gave me close to 60 ml of volume.
The subscription without marking gave me <50 ml for the same weight. That’s allmost a 20 % difference in weight even though they look very similar!
I’ll do another test with an exact number of beans to confirm, but I’ve learned a lot already. Maybe my 1:3,5 ratio wasn’t half bad after all and what to actually expect from such a light roast.
This is cool stuff! Much obliged again!
In all honesty, I think that happiness comes from finding a bean you love and sticking with it. Experimentation has its place, but…
