Wow, that's quite the long-winded title. I mentioned in my post on Sunday morning that it would be good to test if stirring time actually does make a difference with instant coffee. I figured today was a good time to do it, considering I am out of beans, too lazy to go buy some, and desperately in need of coffee: I have no problem drinking three cups in a row in the name of science. So here goes:

Two cups. One scoop each. I pour water into the first one, set the count-down timer on my phone for ten minutes, and start stirring. After two minutes I can't take it any more, and decide that two minutes has to be long enough. I pour water into the second cup, and the stirring parameters are "keep going until it looks like everything has dissolved." This takes about ten seconds.
So, here it is: two minutes versus ten seconds. I tried both black first, then added a bit of milk and tried them both again. I gotta say, while they both had that unmistakable instant sheen, the two minutes cup tasted a LOT more like coffee. I'm not sure if further stirring could have increased this much more; there has to be a point where you've stirred in whatever can be stirred in.
Just for good measure, I tried another method: put the scoop of coffee in, pour in just enough milk to cover the granules, add enough hot water so it's hot (there should still be less than an inch of liquid in there) and start stirring. When you're satisfied with the stirring, water it down with some more hot water, stir a bit more, and start drinking.
It was pretty clear that this was much better again. It looks like the less liquid you're stirring, the more effect it has. Having the milk in there at the start sure made a difference too.
Next time I run out of beans we'll have a look at how much liquid is not enough, try to dissolve two scoops of coffee into a teaspoon of water, and taste the results. I never thought instant coffee could be so much fun.
P.S In case you got really bored reading that entry, consider this: in the title of the first draft of this entry I accidentally wrote "Taste Teste" instead of "Taste Test". Heheh...