Grinder setting swing

MediumRoastSteam

Yesterday something very strange happened (again). I’ve been grinding this particular coffee - Kenyan - at setting 10 on the Niche. Yesterday the shot took 70 seconds for the usual 18g in, 36g out. I thought nothing of it, maybe some freak event, and just drank the coffee. This morning, guess what? Same thing again, but took it even longer, like 85 seconds.

The pressure is building up fine, and the water debit looks fine too.

This happened to me in the past (I had a totally different equipment back then - Pro 700 + Kinu M68), and, back then, I even checked with some colleagues at work and they reported a similar thing!

Has anyone else experienced this?

dutchy101

Ive had back to back wildly different shots using the same bean and grind setting before (on a DF64 as opposed to the Niche).

I have no idea how or why this could happen. I did wonder if it was an alignment issue, but the frind settings I use tend to be pretty consistent day to day once dialled in.

Perhaps it was the temperature / humidity in the air. But very weird all the same

DavecUK

I find that if a coffee is very fresh, sometimes after a few days, it starts to require a coarser grind. Very fresh coffees seem to always require a slightly finer grind until they age a little. I’m not sure why, but It supports my belief that reactions keep going on in the bean long after roasting has completed.

LMSC

By any chance, do you use a paper filter at the bottom? This does influence the pour and hence shot time.

MediumRoastSteam

LMSC do you use a paper filter at the bottom

Nope.

LMSC

MediumRoastSteam For two shots in as many days, I can only think of distribution / puck preparation. 😊

MediumRoastSteam

LMSC - Of course. All of a sudden my distribution/puck prep changed to the point that shots are now talking longer than 70 seconds :-)

Jokes aside… It’s not prep. I actually pulled a third one today. It’s almost as if, for whichever reason, coffee now needs to be ground coarser. Maybe it’s atmospheric conditions combined with the beans aging. Anyway… A couple of days ago and I was on setting 10, now I’m on setting 14!

tompoland

MediumRoastSteam any humidty swings? that can make a VERY big difference to pour times.

LMSC

@MediumRoastSteam

Bizzare, my reply disappeared. I am sure the beans are recently roasted. With my little experience, I find the Kenyans are easy going requiring a coarser grind than less solubles like Gautemala, Costa Rica.

I wouldn’t prefer such a long shot as a long black, I may end up having more acidity than I would prefer. I am ok with < 45s shots. Of course, it is all relative.

MediumRoastSteam

LMSC I am sure the beans are recently roasted.

Nope. Roast date is 11th April 2023. They are kept vac-pac.

tompoland

MediumRoastSteam

More questions in the interests of diagnosis:

Are you using a Niche Zero of Niche Duo? From memory you have a Zero? Just wondering if for some strange reason the grinder is suddenly developed alignment issues.
The beans are several months past roast date. I’ve had beans disintegrate very quickly, like falling off a ledge. That can be even more pronounced with high pressure vacuum packing. Surprisingly, the beans can actually deteriorate faster than beans in a normal bag or canister. @DavecUK alerted me to this so I tested it with the same bactch of beans, half a batch of freshly roasted beans in a bag with a traditional one way valve and the other half vacuum packed after (from memory) around ten days degassing. The latter deteriorated almost twice as fast than the former, as measured by pour times at the same grind size.

Add an increase in humidy?

Following with interest.

MediumRoastSteam

tompoland - hey Tom!

Niche Zero. But also happened a while back when using a Kinu M68 (also a conical grinder).
The strange thing is that it has gone significantly coarser rather than finer.
I can only think it’s atmospheric change. In the grand scheme of things… first world problems, but very strange it happen all of a sudden.

The interesting thing however, is that a month or so ago the opposite happened: I had to, all of a sudden, grind finer. And it happened across all the coffee beans I had on the go. Initially I thought, ok, the beans are ageing, but for all of them to suffer from the same symptom was odd.I even checked my grinder “zero” point, clean it all, and the zero point was perfect where it always been. I had this grinder for almost 5 years now, and as can tell you categorically I did NOT accidentally turned the calibration ring by mistake.

Just very odd, but it happened before, so just curious too if there’s a rational explanation behind the phenomenon.

tompoland

MediumRoastSteam sick puppy that I am, I’m always fascinated by this sort of thing.

And were there any wild swings in humidity that might have come into play?

Just when you think it’s safe to (go back into the water) grind again….

MediumRoastSteam

tompoland - I think we went from very dry warm weather to typical British summer (20C max, drizzle, overcast).

tompoland

MediumRoastSteam spoke with a local barista last summer who works in a cafe that has a massive open front wall, so no air conditioning, just ceiling fans. She said that on some days in summer she has to change the grind setting up to 8 times to compensate for changing humidity. So that may be the answer. (Where I am in Australia we have long dry warm and sunny winters but hot wet and humid summers. Cos we’re upside down n all 😉)

LMSC

I have opened Crankhouse Kenyan roasted on 25 April from VacPac this morning. Ground at #5 on the Duo. The shot time was 38s. Let me see how it fares the next couple of days and come back. I would finish the coffee in 2-3 days though. 😊

thewelshvet

I’ve had this for the first time recently. Have had to radically alter grind on the Zero in the last week or so.

LMSC

Today, the same coffee from Crankhouse, same dose and grind reference ran a little faster and finished at 31s.

JahLaza

@MediumRoastSteam what beans are you using? Is it a blend? This happened to me a couple of times in the past, but it’s probably been about a year ago, and was in the summer when the weather was sticky and humid. I’m pretty sure it was a blend, and would not have been any more than 2-4 weeks post roast. I put it down to the relative humidity and the beans at the time. 🤔

MediumRoastSteam

JahLaza what beans are you using? Is it a blend?

It affected all the coffees I had on the go: all single origins, Kenyan, Brazilian, Colombian.

tompoland

MediumRoastSteam any chance your grinder is in a sunny spot?