Greetings, All!

New to me (used) Breville Oracle user, and I've noticed something I've not seen mentioned elsewhere.

I have experienced the occasional wavy tamp on the double basket when completely dry, which isn't difficult to remedy. However, when running a cleaning cycle I noticed the internal texture of the single basket vs the polished interior of the double basket. (at least on my equipment)


Anyone else confirm this? I can't be certain all of my equipment is factory original, so don't want to assume.

I plan to explore etching or lightly texturing the inside of the basket to see if this makes a difference. Will report back.

Thanks to this forum I confidently purchased a non-working machine and repaired within a few hours. Great forum and members! Thanks.

Warning! Do not use strong acids without experience, knowledge and proper safety. Similar results can be obtained with mechanical texturing.

That being said, here is about 5-10 minutes of acid etching focused on the edges; I didn't want to alter the basket holes/flow.




Based on feel, it is substantially less smooth and polished.

100% dry basket, and no waviness or evidence of a rotating puck. Initially appears to be a very simple success.


Ignore the scales; that's a negative weight due to tare of complete portafilter. And, yes, it's a cheapo scale, I know.

Too early to tell, but I was surprised that my shot tasted different. I will weigh the tamped grinds over next few sessions, something I didn't do as a part of this test so far. How many grams of water/moisture was in the basket before? Enough to matter? With wet basket, was the extraction influenced enough to be noticable vs completely dry basket?

A damp basket may have a tendency extract unevenly compared to a dry basket. Many people, including myself, dry the basket between shots. The self-dosing and self-tamping features of the Oracle seem to be causing you to work harder than you otherwise might need to.

A damp basket may have a tendency extract unevenly compared to a dry basket.

Agreed. At minimum is an undesired variable to account for.

Many people, including myself, dry the basket between shots.

The polished double shot basket seemed to cause problems with the Oracle auto tamp when dry. Clearly a dry basket is standard and desired MO.

The self-dosing and self-tamping features of the Oracle seem to be causing you to work harder than you otherwise might need to.

This machine is in a location where manual weighing, grinding is not an option. I would reiterate that I have no complaint; I simply discovered the lack of basket friction may be a primary contributor to the wavy tamps I previously experienced, saw others comment on, and wanted to solve without depending on a prewetted basket.

And 15 minutes seems to have addressed this matter, but I hadn't seen any references to this as a solution. And after finding such value in the information found here I wanted to give back. I was simply sharing the process as I identified and found what seems to be an easy fix.

I understand the limitations and why the Oracle is a reasonable choice for your situation.

I seem to recall that the La Marzocco Swift, another self-tamping grinder, worked better with its own baskets. I vaguely recall that they were also not highly polished on the inside. If they fit the Oracle, they may be another option that doesn't involve etching the sides of the basket. It looks like they are available in at least 19 or 22 mm depth through Espresso Parts ("EPNW") for under $23 today.

I'd be interested in hearing of how you etched the basket, perhaps in another thread. The people exploring third-generation baskets are finding that unpolished sides are different than polished sides. Being able to dull the sides without either directional marks or using media blast is something that group might be interested in.

I'd be happy to share anything I can. I'm completely new to posting to this forum, so I'm not sure how or where to post details of the acid etching process I used.
All I can say after both sampling and wasting way more beans than one should in a day, I'm confident in both the diagnosis and resolution.
Honestly, if others can confirm breville continues to produce smooth/polished double baskets (while ironically producing textured single baskets), the solution is a DIY simple fix and breville should make this simple change. And it would beg the question... If the benefit of a textured single basket was known, why produce or use a stamped, non-textured basket that everyone uses?

I'll consider it speculation at this point, but weights and measures are pointing to the smooth, polished double basket as being the largest culprit. I'll report back, but initial results are far more consistent with a textured basket.

This has been a marked improvement in obtaining more consistent grind weights. It also appears to be removing the inconsistency in back to back shots using the Oracle's timed shot extractions.