A high quality bean, appropriately roasted, relatively fresh, freshly ground immediately before use with a bur grinder, and then your choice of method, plenty of grinds but almost always hot water, and preferably some pressure to extract oils, finally filtered through paper.
My weapon of choice is an aeropress or a manual espresso press. An Americano is arguably superior to a cup of drip. I drink it black.
1) Really, really, really shitty coffee that just tastes like bitter and stale, always. Often lots of ash tray in the flavor. (instant, many k-cups, some exceptionally bad gas station coffee, very bad pre-ground coffee usually bought in a large tin [though not all of that!])
2) Normal coffee. It is coffee flavored. It might taste very burnt if it's a dark roast. It might be bad coffee flavored, or good coffee flavored, but it is coffee flavored. This is nearly all coffee you buy at stores like Target. Ground or whole bean and preparation method makes a little difference, but not really that much. Anything involving a filter versus French-press will be fairly different, but that's about it.
3) Fine coffee, prepared well. It's... heavenly. Delicate. Notes of herbs and berry and all kinda of crazy stuff, clear enough that even this guy's crappy palate can pick it up. It's really expensive. It's basically a whole different drink from the entire rest of "coffee". It goes stale in maybe 3 days after opening the bag, so buying more than a little at a time is a bad idea unless you have many people drinking it. I've not found any method to preserve it longer that actually works.
Vacuum packer is a thing I don't have. Might work. I've heard conflicting things about freezing (I've tried it with lesser beans in Tupperware, didn't seem to make much difference either way)
unless the tupperware is completely airtight, oxygen will still leak into the container and cause oxidation. This deteriorates the bean.
The cold temperature will slow evatoration of the volatiles from the bean, but it is unstoppable.
Vaccume sealing will drastically slowdown the oxidation, but since you cannot truly get a 100% vaccume, there will still be some oxygen in the bag, which will cause oxidation anyway. It will just be a bit better than nothing.
And then unthawing the beans requires a moisture free environment (e.g, take it out of the freezer for 24hrs without unsealing it), or the beans will spoil. Once unthawed, i dont believe refreezing will work - it will just spoil it.
So yes, preserving beans' freshness is difficult, and bound to fail eventually. Might as well just pay for fresh beans, and pay for the transportation and packaging (which, i guess is the overhead, and makes buying small quantities more expensive...)
I don't notice much difference on the mid-grade beans until a week out, but the expensive top-end stuff is going downhill on day 4, maybe day 5. It's not ruined yet, but if you paid 50-100% more than for mid-grade beans, it's not ideal.
A high quality bean, appropriately roasted, relatively fresh, freshly ground immediately before use with a bur grinder, and then your choice of method, plenty of grinds but almost always hot water, and preferably some pressure to extract oils, finally filtered through paper.
My weapon of choice is an aeropress or a manual espresso press. An Americano is arguably superior to a cup of drip. I drink it black.
Coffee is fucking delicious.