h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

I have had disscussions with many people about how tightly packed grounds should be for use in various espresso makers. Everyone seems to have a different opinion and makers instructions seem to vary from pot to pot and machine to machine or be vague in the 'pat down but not too hard' vein.
Anyone know any hard and fast rules for the best results?

I would love to know the answer to this! I have a fairly good quality espresso machine and one of those electric bean-grinding machines. I find that any pressing down at all results in the container holes getting blocked by very fine grains of coffee (it doesn't matter how coarse the general grind is - there is always a bit of the super-fine stuff) followed by a near-terminal build up of pressure in the machine. Is there any way to stop this? The freshly ground stuff tastes so much better than the pre-ground store-bought stuff.

My machine came with a little plastic plunger for tamping down the coffee. I sometimes forget to use it and it doesn't seem to make any difference.

It's all down to the size of the grind. My Gaggia works best with a number 4 grind (from Whittards) and a light tamp - gives a beautiful crema. Anything smaller and tamping is a waste of time - takes forever to get the coffee through.

It's pretty much a case of trial and error - get the grind right and the tamp right, and you'll soon know you've got it.