99% is that you tamp it wrong and is some cases water makes channels.

If the shot is flowing down one side more than the other, then you need to work on the distribution and tamp. You want to make sure the grinds are distributed evenly across the basket and that a level temp is done. Using a naked portafilter will help identify issues with the distribution and tamp. Uneven distribution and tamp will mean the tail is not centered. And channeling will result in a rough tail or spritzes along the side.

Oracle grinds and tamps for me. I haven't adjusted the tamp setting at all. If I'm not mistaken, default tamp is set at 5. Any suggestions?

I don't understand naked portafilter... how does this work?

A naked portafilter is one where the the bottom has been cut off, including the spouts, so that you can see the bottom of the basket. You can see all the problems with an extraction this way.

Here is an example... If you were to use a naked portafilter, most likely it would show that your "tail" is not centered. This is a problem w/ distribution and tamp of grinds in the basket.

susanc wrote:Using the pressurized basket...
...Then tried 24, 26, 28 still fast flow on right.
...right spout just a bit faster than left.

So now I switch back to non pressurized at 30...
...the flow from the two spouts are even.

Assuming the uneven flow is relegated to the pressurized basket only, I wouldn't worry about it. The pressurized basket has only one pin hole for the espresso to flow out of and portafilters that employ this type of basket generally have a small sump in the bottom to collect and redistribute this single stream. As long as the two spouts flow ok with the non-pressurized basket, you should be good to go.

Cheers!

- Jake

Thanks Jchung. Will try to look for naked portafilter ... curious to find out if I need to change Tamp setting

I learned from YouTube that changing the Tamp setting from 9 to 1, changes the grind output by 1 gram. Mine is still set at default 5. Will try this out too.

Thanks much

----

Hi Jake.

I use pressurized basket for barista express and I get even flow both spouts. But for oracle using pressurized basked I get uneven flow and it also spritzed air while flowing.

Oracle doesn't come with pressurized basket. I think what we bought as an accessory could be for another model of Breville. Amazon sells 58mm pressurized that fits 900 and 920 only. It says does not fit 980. And when I checked the 980 manual it came only with single and double non pressurized baskets without any mention of using pressurized baskets.

So going back to non-pressurized, if I want a thicker flow, I should increase my tamp setting? If 9 setting output was 21 and 1 setting output was 20 from demo in YouTube.

Thanks much Jake.