I've had a Breville BES820 for a number of years now but my grinder was never very good.
So I recently purchased a Breville Smart Grinder and started using Single wall baskets.
Unfortuantely I don't seem to be able to get any consistency with my shots.
Sometimes they are wonderful with a lovely smooth crema.
But often times I am getting no Crema at all.
I use freshly roasted beans .. these ones were roasted just a couple of weeks ago.
Also I do preheat the coffee machine first. The BES820 has a pressure gauge that shows GREEN .. OPTIMUM .. RED. When it hits Optimum then the shots are always good. But it seems to just get to GREEN and then no Crema.
Is the problem with my tamping? I don't really know much about that other than only tamp once
with not too much pressure .. but I've tried with lots and little pressure.