We would say that the 'perfection of the grind' is probably the most important ingredient in making perfect espresso. We used to make the rookie mistakes and thought that a finer grind would always produce a better espresso…not the case!
When you analyze the coffee grounds after use, you’ll know whether or not you should go coarser or finer. Even though espresso machine manufacturers are getting better at making portafilters that make it easy to produce a nice espresso, it is still important to have the grounds perfect for your machine. Having the coffee to coarse is also a negative because it won’t produce the most flavorful tasting espresso.
The reason there is less taste comes down to the mathematics of it all. Let me explain, the water doesn’t go “through” the coffee grounds, it runs between them and washes out the oils and flavour into your cup. A single coffee ground has a specific “surface area”. Taking that same coffee ground and splitting it (grinding finer) takes that same surface area but adds to it the inside of the split parts, therefore giving more surface area for the water to pass over, in-turn producing a better tasting espresso. You can also add more surface area by adding more grounds. A little off topic...I’ve said it before, if I ever was elected for government and had the power to pass laws, I would make it illegal for anybody to freeze bread. Yes, I would pass a law to arrest anybody who had bread in their freezer. Both my parents and my mother-in-law would be the first in prison...for life of course! Bread is something that should be baked and eaten. The leftovers can be made into bread crumbs or used for other cooking ideas but NEVER EVER as tomorrow’s bread. Coffee should be treated the same, you should buy only what will be consumed within a specific timeframe. Each of us will have a different timeframe but I would say personally, if your grounds are not used up within two days, you’re grinding too much.
Coffee beans start going stale as soon as the roast is completed. The process is expedited upon grinding. Now, have you ever taken a fresh loaf of bread, cut it in half and left it? After a few hours, the now exposed inner parts of that bread isn’t soft anymore and if left for a longer period of time, becomes harder and eventually stale. Each Coffee Bean is like an individual loaf of bread. It has an outer crust that once exposed will immediately starts its voyage to “Stale-ville”. So the most ideal situation would be to have your espresso beans ground right before usage. It’s so important that you don’t keep your coffee (beans or grounds) in your freezer or fridge! (More on this in Vol 3: Coffee Storage)
