What is the downside with having too much headspace vs too little?

I've been using a triple basket lately, by accident at first, and a 18 gr dose with the Strega and have been getting extremely consistent even pours with this combination. Having said that, I also switched back to a flat tamper about the same time as well.

On most machines, I don't think there's much of an effect on taste if dose and grind are the same (i.e. you use two baskets with identical hole areas, but one deeper then the other). The major difference will be that the puck gets soggy with more water if there is plenty of headspace and room for the puck to expand. This is certainly true with the Strega and other levers, where there's already a column of water above the puck.

The exception are the Brasilia style groups you find on Elektra machines, and some Bezzera and Brasilia machines. These have almost no water in the group above the shower screen. For some reason I can't fathom, this means that whenever the puck cannot fully expand, the shot always ends up dramatically underextracted and rough tasting.

But remember, your question would strike a traditional Italian barista as clueless: for them the fundamental problem with American espresso is overloaded baskets, not insufficient headspace, and pucks that cannot get fully soaked.

The pucks still seem very firm and dry enough, popping out in one piece, leaving a fairly clean basket. Maybe not quite as dry as with a double basket and normal headspace but, it's hard to tell any difference just from casual observation. And certainly they're still much drier than the pucks I routinely get out of the Unica.

And if there's no taste difference, I can't see any downside to leaving well enough alone and sticking with the triple baskets.

Thanks.

We discussed it for several days, take a look at this thread....

My failed headroom experiment

Thank you Dave