I have a question: which is the most efficient way of stirring milk and/or sugar into coffee?
I’m torn between the spoon (because it has a larger surface area) or a fork (because the tines might create more turbulence in the cup). I think the stir stick would take more stirring to evenly distribute milk or sugar.
I know this is utterly trivial, but it’s the sort of thing I wonder about.
I take my coffee unpolluted so I have no direct experience, but I do have a little intuition about fluid dynamics. My WAG is that there would be very little difference between the fork and the spoon. The spoon will create fewer but larger vortices and the fork will create more smaller vortices. Both will provide effective mixing in the limited volume. I’d favor the spoon for several reasons:[ul]
[li] the spoon will be more effective at scraping undissolved sugar off the bottom of the cup[/li][li] larger vortices are prettier, and milk in coffee creates great flow vis[/li][li] Opal uses a spoon (cites available upon request)[/li][li] a spoon is more eco-friendly if you already use a spoon to scoop the sugar (since you won’t end up washing two utensils). If you use little landfill-clogging paper packets, feel free to use as many stirring utensils as you like.[/li][/ul]
Can’t answer the OP, but I know this:
Stir with a knife, stir up strife!
(God, if I had a dime for every time my friend John told me that on our camping trips when all we had to prepare coffee was a Swiss Army knife, I’d be a second Bill Gates!)
My coffee technique, of which I am proud.
1.) Prepare cup, sugar, and cream. Mise en place!
2.) Put sugar in the cup first.
3.) Pour in coffee, immediately dissolving sugar and stirring itself.
4.) Add cream to the still swirling coffee/sugar solution. by the time the coffee reaches your lips, all will be incorporated perfectly.
5.) Smugly drink the wonderful elixer, reveling in your efficiency.
No stirring needed!
I’m not actually anal retentive, (Hyphen, I know:D), I just like to make my coffee experience as quick as possible while at my local 7-11 with a line of construction workers behind me.
Martin
Who really prefers Turkish Coffee, but does use other caffeine delivery systems.
I say spoon. The turbulence created by the fork is localized. A spoon will get all of the coffee swirling.
Me, I’m too lazy to find a spoon and wash it afterwards. I just put the milk/cream in the cup first so it gets stirred when I pour the coffee. (No sugar for me)
By the way, welcome to the board!
My theory is that as one feels more resistance when stirring a spoon, more liquid is being moved, so the mixing would be faster. This does completely ignore the effects of vorticity, so there’s probably a delicate and cunning balance that would involve detailed calculations I’m not equipped to do (fluids was second only to thermodynamics on my “loathed subjects” list).
The clear solution is to use a spork.
Actually, I add the sugar and pour in the cream to dissolve the sugar- sometimes swirling it once or twice- then pouring in the coffee completes the dissolution. 
PC
I detect a flaw in your method. The cream would retard the dissolution of the sugar, resulting in what I call “The Dunkin Donuts Effect”. This leaves some sugar crystals undissolved in the bottom, or at best, varying strata of sweetness. I take my DD swill rather sweet, more so than actual quality coffee.
Perhaps an actual physicist could weigh in here.
Martin
i use a fork, more turbulence (which is what causes the solution to become mixed).
What stirs coffee best?
A wife who knows her place in the world!