I got a new (used) espresso machine a couple months ago and from the start have been using the single basket with good results. However, I have not once gotten a decent shot out of the double basket! (ie a fast flow and just a hint of crema around the edges)

Are there some general rules about this sort of thing? Grind? Tamp?

One (probably) important detail is that with the single basket I get the best results with a few vertical taps to settle the grounds then a very light tamp. I've been trying the same with the double.

Well just writing this down is giving me some ideas, but I'd still appreciate any more input!

Thanks, Henry

hbuchtel wrote:
Are there some general rules about this sort of thing? Grind? Tamp?

General rule with singles is that everything you know from doubles is wrong. The reverse is probably true as well. Start with grounds level in the basket before tamping, tamp to thirty pounds, and run a shot. If the shot is fast, grind a bit finer. Repeat as necessary 'til the shot is between 1-and-a-half oz and 2 oz in twenty-five to thirty seconds.
Of course, fresh beans, good grinder, right temp, right pressure, et al.

I almost never use my single basket because the techniques are so different. It's far less frustrating for me to throw away a half a double, if there were any reason for me not to immediately quaff it.

Psyd wrote:It's far less frustrating for me to throw away a half a double, if there were any reason for me not to immediately quaff it.

Heh heh!

That's just the thing . . . at ~18g a pop I don't want to do much experimenting!

Hope to get some good results this afternoon.

Henry

hbuchtel wrote:at ~18g a pop I don't want to do much experimenting!

Go buy some cheap beans at the grocery just to experiment with. Once you start to get good at it, drink one. Just to remind yourself why you spend so much on beans... ; >
Remember, fresh beans (once you have the technique figured out and switch back) are going to want just a hair coarser grind than stale beans.

We have to grind slightly coarser if we are using a single basket. (2 notches on the Mazzer).
Keep your tamp the same, adjust your grind.
You should be able to do both single and double equally well.
Pay attention to your distribution and level tamp.

Good Luck.

Henry,

Depending upon the method you are using it could be a dosing problem. Methods that work appropriately for a double don't necessarily work for a single and vice versa.

I don't dose by weight or even by the doser on my grinder. For a double I dose until the basket is overflowing and then wipe off the excess grounds until they are even with the rim of the basket. Tamping then results in the top of the puck about level with the ridge of the basket.

Early on I tended to have the opposite problem that Henry describes--singles that pour too slow (instead of doubles that pour too fast and thin). The problem I had was from levelling grounds at the top of the basket for a single. This causes a single basket to be overdosed because the shallower depth of the basket does not allow as much compaction from the tamp. So the top of the puck ends up well above the ridge. The result is a choked machine. The solution is to dose below the top of the basket for a single. With some practice I've learned how to eyeball the dose with a quick wipe of my finger.

Henry, you could be doing the exact opposite. If you are grinding and dosing right for the single, then the method you are using may be underdosing the double basket. Alternatively, if you are putting enough coffee in the double basket (i.e. tamped puck is about level with the ridge or leaves a few millimeters between it and the dispersion screen with the portafilter in the machine), then you will want to adjust your grind finer and dose slightly less with the single to compensate for the finer grind.

You don't say what your method is so I can't really tell whether this is on the right track. Just an idea worth looking into. BTW, tamping beyond about 10 pounds makes a negligible difference.

Cheers,
Ken

hbuchtel wrote:I got a new (used) espresso machine a couple months ago and from the start have been using the single basket with good results. However, I have not once gotten a decent shot out of the double basket! (ie a fast flow and just a hint of crema around the edges)

Are there some general rules about this sort of thing? Grind? Tamp?

One (probably) important detail is that with the single basket I get the best results with a few vertical taps to settle the grounds then a very light tamp. I've been trying the same with the double.

Well just writing this down is giving me some ideas, but I'd still appreciate any more input!

Thanks, Henry

Henry,
The responses you've gotten so far have been on the mark. I just wanted to add that a double basket has a much larger effective egress in its filter than the single basket does, and so the flow will be a lot greater through the double basket. To compensate for this difference in baskets, you can do any or all of the following when using the double basket:

1. Grind a notch finer than you did for the single
2. Increase the dose to slightly more than double the dose of the single, thwacking the basket across the top with the edge of the measuring spoon to settle the coffee (as if you were chopping chives with a chef's knife) or by giving the PF a few gentle whacks on the countertop and then adding some more coffee to the basket in the room created
3. Preinfuse longer, to allow the coffee to swell

Regards
Timo
P.S. What machine are we talking about?

Thanks Timo.

I've been aching to try out the ideas above but ran into a patch of busy-ness where I've had no time for trying new things.

The machine in question is the Zerowatt (gravity-fed lever).

Henry

You could bake a birthday cake in the Zerowatt's huge double basket. My money's on increasing the dose and making the grind one notch finer.

Regards
Timo