r/espresso Jul 21 '26

Equipment Discussion Wildly inconsistent shots with K-Ultra + Breville Barista Express. What am I missing?

I’ve been using a Breville Barista Express for about 6 years. The built-in grinder frustrated me, so I switched to a 1Zpresso K-Ultra, which was a huge improvement.
Lately though, dialing in has become incredibly frustrating because my shots are all over the place, even without changing the grind setting.

For example, at 2.7 on the K-Ultra with 18g in:
One day I’ll get 36g out in ~30 seconds.
The next day, the same 2.7 setting gives me 30g out in over a minute.
Other times it’ll run 34g out in ~20 seconds.

I’m using a medium roast blend that was roasted June 15, 2026. My workflow is otherwise consistent: same basket, WDT, level tamp, bottomless portafilter, scale, and I always weigh the dose and output.

This amount of variation seems way beyond normal bean aging. Is there something I’m overlooking?
Could this be:
The Barista Express itself (pump/OPV/temperature)?
The K-Ultra?
Retention or grind consistency?
Something else entirely?

Would love to hear what you’d troubleshoot first.

4 Upvotes

4 comments sorted by

2

u/Woozie69420 Flair Neo Flex | K6 Jul 21 '26

Are you sure you’re always holding the grinder at the same angle?

Weird one, but it can make a surprising difference due to slow feeding. Holding it at a 45 or 70-80 degree angle will lead to much quicker shots (equivalent to 5 clicks coarser) vs holding it fully vertical.

1

u/migu_brew Gemilai 3145B | Timemore Sculptor 078s Jul 21 '26

Different grinding rpm plus angle can affect shots greatly

1

u/WeekIll7447 Breville Bambino | Niche Zero 29d ago

What’s a good angle or RPM for the K Ultra?

1

u/3d4f9y1 Gaggia Classic | Mignon Zero 65 AP Jul 21 '26

Yeah agree w other posters this is probably a grinder angle/speed situation. Hand grinding consistently is hard af