I have this problem lately with the double shots I try to pull.
In general I stop the machine when blonding occurs, paying very little attention to volume of shot produced. 90% it is a little above 60ml (including crema) which I believe is quite ok. (BTW when we talk about a 60ml double shot should the crema volume be included? I say yes, but I have been served many times an espresso measuring around 100ml or more including the crema volume).
I believe I am pretty consistent and my shots taste the same day after day... not perfect, but the same.
Recently I notice a decreased volume of shot approximately to half. As I said I stop the machine based on color and not volume.
It still comes at the same time (today I timed it around 27 seconds) and tastes exactly the same. I am used to that taste and I believe I would notice any deviations.
There are no visible channeling holes in the puck. I don't have a bottomless pf to check but the blonding is normal, not sudden. Although I have never seen sudden blonding to know what we are talking about.
What is even stranger is that when this happens, the shot produced (single), is by far better than any shot I have managed to pull with the single basket.
It is still a problem though, since I almost always use the double pour to pull two singles, so I end up with two halves. Plus it's a waste of beans/money to produce singles from double doses. And of course it shows that something is wrong.
Any help would be appreciated.

If it makes any difference I am using a Rocky doserless set at 4 and a Gaggia Espresso, not using the rubber thing in the pf (don't know how they call it, it is useless in my opinion)

Thank you all in advance,
Iason

tJasC3 wrote:...when we talk about a 60ml double shot should the crema volume be included?

Yes, the crema is included. Or if you wish to be more precise, use the brewing ratio.

tJasC3 wrote:What is even stranger is that when this happens, the shot produced (single), is by far better than any shot I have managed to pull with the single basket.

That's a good thing, right? Seriously, what you describe sounds like a ristretto. Not sure why your pour volumes would suddenly change; if the grind setting is the same, a change in the dose, tamp, brew pressure, or even humidity could account for it.

Well maybe some environmental changes. No change in my tamping or dosing for sure.
Now for the grind... is there any case of the grinder being so messed up that it has gone so inconsistent?
I have the grinder only for a week and I moved it to around 40 to grind for french press and when tried to get it back to the fine setting it stuck around 20. I thought a bean might have been caught in so I pressed the button for a split sec and then moved it down to 4. Is there any way I might have damaged it?
4 is not too low. The burrs don't even touch at zero. More something like -3 (though I haven't removed the screw to check).
Thanks again,
Iason

tJasC3 wrote:Now for the grind... is there any case of the grinder being so messed up that it has gone so inconsistent?

Rocky is known for thread slope (fix), but that wouldn't account for more than a few seconds difference in pour speed. Have you checked the brew pressure?

tJasC3 wrote:Is there any way I might have damaged it?

No risk, the burrs faces are parallel; see Damage espresso grinder burrs by adjusting them too close? for explanation.

tJasC3 wrote: I moved it to around 40 to grind for french press and when tried to get it back to the fine setting it stuck around 20. I thought a bean might have been caught in so I pressed the button for a split sec and then moved it down to 4. Is there any way I might have damaged it?

If there were some large portions of bean left in between the grinder faces, and the grinder were adjusted without the grinder running, couldn't this have done something evil to the grinder? If not, then why does nearly every manufacturer of grinders (that I know of, which may be a smaller group than you'd think) suggest that it not be adjusted while static?

Psyd wrote:If there were some large portions of bean left in between the grinder faces, and the grinder were adjusted without the grinder running, couldn't this have done something evil to the grinder?

Indeed, moving the setting finer without running the grinder risks stalling / overheating the motor. That is not a good thing.